Abstract

In this article, a InP based strain-balanced In0.58Ga0.42As/In0.47Al0.53As quantum cascade laser emitting at 7.7µm is reported. The active region is based on a slightly-diagonal bound to continuum design with 50 cascade stages and a low voltage defect Δinj of 96 meV. By optimizing the active region and waveguide structure, the waveguide loss αw of 1.18cm−1 are obtained, which contribute to a high wall-plug efficiency (WPE) of 9.08% and low threshold current of only 1.09 kA/cm2 in continuous-wave(CW) operation at 293K. The maximum single facet output power of 1.17W in CW operation and 2.3W in pulsed operation are measured at 293K. The narrow ridge and buried ridge structure epi-side-down-mounted on the diamond heatsink improved the heat dissipation of the device. A beam of pure zero order mode and a broad external-cavity tuning range from 7.16µm to 8.16µm are also achieved.

© 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

1. Introduction

The LWIR (7-14µm) region contains an important atmospheric windows [1], and most of the molecules have strong absorption bands in this region including CH4, SOx, NOx, NH3, etc., which is very suitable for trace gas analysis [24]. Quantum cascade lasers (QCLs) is a new type of laser source based on electron transition radiation between intersubbands, and its emission wavelength can cover the middle and long-wave infrared (MIR&LWIR) and even terahertz through bandgap engineering [5]. Owing to QCLs’ advantages of portability, high stability, continuous-wave (CW) operation at room temperature, wide tuning performance and high power, QCL gradually replaces other lasers and becomes an ideal MIR&LWIR light source for trace gas sensing. For commercial application, gas sensing systems usually need to minimize power dissipation under the condition of ensuring device size and performance, in other words, improve device high wall-plug efficiency (WPE) [6]. Higher WPE means less heat generation in the active region, better device stability, and also longer lifetime.

The WPE can be expressed as ηwpe = ηi ⋅ ηo ⋅ ηv ⋅ ηe, where ηi, ηo, ηv and ηe are internal quantum efficiency, optical efficiency, voltage efficiency and electrical efficiency respectively [7,8]. Generally, the longer wavelength of QCL, the smaller WPE is, especially for LWIR-QCL (7-14µm) and even far-infrared (14-30µm), which is mainly due to the following reasons [9]: Firstly, the free carrier absorption loss is proportional to the square of the wavelength, which will increase αw and reduce ηo. Secondly, as the wavelength increases, the ratio of photon energy and voltage defect Δinj (defined as the difference in energy between the lower energy level of the current period and the upper energy level of the next period) decreases, and then ηv decreases. Thirdly, in order to reduce αw and improve Γ, lower and thicker waveguides are introduced. However, thick waveguides are not friendly to heat dissipation, resulting in increased thermal accumulation in the core layer, increased thermal backfilling current, reduced slope efficiency and other degradation phenomena of device performance. From the above, lower Δinj, αw and thermal optimization contribute to a higher ηwpe of LWIR [1].

In recent years, a lot of efforts have been made to improve the performance of LWIR devices, but the focus has been on the wavelength of 8-12µm [1013] and even >12µm [14,15]. However, the wavelength of 7-8µm region was also important for trace gas sensing, where strong molecular absorption peaks of CH4 and N2O are concentrated [2,4]. It is worth noticing that CH4 molecular absorption spectral lines in the MIR are only concentrated in the range of 3.2-3.6µm and 7.2-8.1µm, the absorption spectral lines at 7.7µm are clear and easy to be recognized [3], which is very important for CH4 trace gas detection. QCLs emitting in the 7.3 to 7.85 µm region were reported in 2010 [16,17], but none of these devices exceeded 1W in power and the maximum WPE was only 5%. Besides, Richard Maulini et al. introduced a model for backfilling of the lower laser level in 2011 [1], they believed that the traditional model strongly overestimates backfilling at low voltage defect, predicting an optimum LWIR voltage defect of ∼100 meV for achieving maximum WPE at room temperature, which was applied in a 7.1µm QCL, giving a maximum CW output power of 1.38 W and maximum WPE of 10.0%. Up to now, the highest WPE in CW operation in 7-8µm is obtained by a high differential gain QCL with a wavelength of 8µm reported by Wenjia Zhou and Quanyong Lu et al [18] in 2019, which reported a high WPE of 20.4% in pulsed mode operation and 12.8% in CW operation, and a CW output power of 2.0 W is achieved from one-side of a single-element QCL using epi-layer down bonding, and the front and back facets are anti-reflectance(AR) and high-reflectance(HR) coated respectively. Furthermore, there were some novelty works reported by Botez et al. They introduced active structure design called step-taper resonant extraction (STA-RE type) [1921] and obtained very high internal efficiency ηi of 81% at 7.79µm and 86% at 8.8µm. The single-facet power of 7.79µm device was up to 1 W in CW, at a heatsink temperature of 14 °C, and the maximum achieved single-facet CW wall-plug efficiency is 6%. Besides, the characteristic temperatures T0 and T1 were obtained to 228 K and 529 K, respectively, which were very high when compared with conventional QCL. However, the material epitaxial process of this structure is quite complex.

Therefore, a watt-level QCL emitting at 7.7 µm with a high WPE and operating in CW mode at 293K is reported in this paper. The strain-balanced design was used to reduce leakage current. By optimizing the number of active region stages and waveguide structure, we improve the Γ and reduce the αw successfully. In addition, buried ridge structure and diamond heatsink are adopted to improve the heat dissipation performance of the device. These measures all contributing to a high WPE.

2. Laser active region, waveguide design and experiment

The λ ∼ 7.7 µm high wall-plug efficiency watt-level CW QCL operating at room temperature reported here was based on a slightly-diagonal bound-to-continuum(BTC) design, and the strain-balanced material In0.47Al0.53As/In0.58Ga0.42As with ∼0.36% strain were used in the active region to increase the conduction band offset to ∼608 meV and prevent carriers’ from escaping into the continuum, which was different with the previous reported structure emitting at 8µm [22]. The BTC active design has several advantages: high fault tolerance for material growth, high temperature performance, broadband gain [5], large oscillator strength and good lifetime ratio of upper and lower energy level contributing to a large internal quantum efficiency ηi. Therefore, the design applied here is particularly suitable for LWIR devices.

The active region of the laser was grown by molecular beam epitaxial (MBE) equipment, and the specific thickness of the In0.47Al0.53As/In0.58Ga0.42As had been modified based on the Ref18 published previously with a lattice-matched structure emitting at 8µm. The layer sequence of one period of structure in nm, left to right and starting from the injection barrier, was 4.1/1.8/0.92/5.3/0.92/4.9/1.0/4.1/1.8/3.4/1.74/2.94/1.94/2.83/2.86/2.73. The In0.47Al0.53As layers are in bold font, and the In0.58Ga0.42As wells are in normal font, and the underlined layers are doped to n=1.5 E17cm−3.The conduction band diagram and wave-functions of different energy levels of the active region under an applied electric field of 53KV/cm are showed in Fig. 1. Introduction of low strain increases the conduction band offset and allowed higher ΔEC5∼155meV and ΔE54∼70meV, which effectively suppressed the leakage current and then reduced the threshold current density Jth. A slightly-diagonal transition was used to reduce the overlap of the wave functions between the upper and lower levels, which effectively increased the carrier lifetime of the upper maser level and reduced the probability of carriers’ thermal backfilling contributing to high ηi and temperature performance. The laser transition matrix element, transition lifetime between the upper laser level 4 and the lower laser level 3, the upper laser level lifetime τ4 and the lower laser level τ3 were calculated to be Z43=1.7nm, τ43=2.97ps, τ4=1.18ps, τ3=0.18ps, respectively. The ratio of τ3 and τ43 was calculated to be as lower as 0.061. Besides, a low voltage defect of Δinj = E3-Eg = 96meV was applied here to ensure a higher ηwpe, which was very close to the optimal voltage defect value of Δinj∼100meV in LWIR region reported in [1]. Because high differential gain of active region can compensate for an increase in thermal backflow due to a low Δinj [17].

 figure: Fig. 1.

Fig. 1. Band structure and wave functions of relevant energy levels of a bound to continuum and low voltage defect low strain-balanced In0.47Al0.53As/In0.58Ga0.42As LWIR QCL active region design for emitting at λ ∼7.7µm under an applied electric field of 53 kV/cm. The upper (level 4) and lower laser levels (level 5) are shown in red and blue, respectively. The ground state of the injector (level g) is shown in cyan. The red arrow marks the radiative transition.

Download Full Size | PPT Slide | PDF

Detailed layer structures from the InP substrate (Si, ∼3 E17cm−3) consists of a 4.5µm InP buffer layer (Si, ∼3E16 cm−3), a 50-stage laser core (Si, ∼1.5E17 cm−3) sandwiched between two 300 nm InGaAs (Si, ∼4E16 cm−3) layer to improve the optical confinement of active regions, a 4.5 µm InP cladding layer (Si, ∼3E16 cm−3), a 0.85 µm graded doped InP layer (Si, ∼1.5E18 cm−3) and 0.15µm highly doped InP cap layer (Si, ∼5E18cm−3). InP buffer layer and cladding layer are thicker than previously reported references for λ between 7∼8µm, which contribute to a lower αw and higher Γ. Two InGaAs layers also help to improve the Γ. The metal organic chemical vapor deposition (MOCVD) is used for all layers’ growth except for the active region and two InGaAs layer, which are grown by MBE.

3. Optical and thermal simulation

An effective way to improve WPE is to increase the number of active stages(NS). Principally, it can reduce the threshold current density Jth by increasing the modal confinement factor and decreasing the waveguide loss, according to the expression of the $ {J_{th}} = {J_{t{h_0}}} + {J_{t{h_{leak}}}} + {J_{t{h_{bf}}}}$, $\; {J_{t{h_0}}} = \frac{{({{\alpha_w} + {\alpha_m}} )}}{{\textrm{g}\Gamma }}$, where ${J_{t{h_{leak}}}}$ and ${J_{t{h_{bf}}}}$ are the leakage current density and backfilling current density at threshold, respectively [8]. Qualitatively speaking, increasing NS is equal to increasing the thickness of the active region, which means that the light is more restricted to the core layer, and the free carrier absorption outside of the core layer reduced. As a result, the αw is reduced and less gain is required to for lasing [6]. Therefore, we numerically simulated the influence of NS on αw and Γ, the results are shown in Fig. 2. Results confirmed that with the increase of NS, the αw decreases and the Γ increases.

 figure: Fig. 2.

Fig. 2. The calculated waveguide loss αw and confinement factor Γ of the 7.7µm QCL as a function of the numbers of QCL-stages from 30 to 70.

Download Full Size | PPT Slide | PDF

However, the active region of the device is consisted of a multi-layer quantum well/barrier pairs, which leads to a significantly lower thermal conductivity in the epitaxial direction than the bulk material. In other words, there is a great heat accumulation in the core layer when the laser works. The increase of NS aggravates the heat accumulation and increases the temperature difference between the core and heatsink(ΔT), which in turn worsens the performance of the device, such as the decrease of WPE and the service lifetime. So it is important to balance the advantages and disadvantages of increasing the NS and find a suitable value.

To this end, we also numerically simulated the maximum temperature(Tmax) and average temperature(Tave) of the core layer change with NS, the results were shown in Fig. 3. And the buried ridge waveguide structure introduced in this simulation will be described later. Combined with the information obtained in Fig. 2, we can see that αw changes slow and ΔT increases more when NS increases to more than 60. We finally chose the NS = 50, and a low αw of 1.15cm−1, high Γ of 66.5% and ΔT of 77.3k were calculated, which contributed to an extremely low Jth and good high temperature performance and were showed in the next part.

 figure: Fig. 3.

Fig. 3. (a) The detailed structure of the device and temperature distribution of a buried ridge QCL epi-down bonded on a diamond heatsink for CW operation. (b) The maximum (Tmax) and average (Tave) core temperature of the buried ridge QCL under CW operation as a function of Ns (Theatsink=300K).

Download Full Size | PPT Slide | PDF

4. Fabrication, packaging and characterization of the device

The ridge-type waveguide structure of the laser restricts almost all the heats generated in the active region to the inside of the ridge. The increase of ridge width is not conducive to the lateral dissipation of the heat in the active region [23]. However, a narrow ridge will reduce the device power and increase the far-field divergence angle. Considering the above reasons and combining with previous experiences, we chose an 8µm ridge width for the device. A buried heterogeneous(BH) structure was introduced into this device: Semi-insulated InP: Fe with high thermal conductivity was grown on both sides of the ridge through selective epitaxy by MOCVD, replacing SiO2 insulation layer with extremely low thermal conductivity. As a result, the BH structure greatly increased the lateral heat dissipation and reduced the temperature of the active region, which was very beneficial for the fabrication of high-power CW-QCL operating at room temperature.

To further improve the heat dissipation and achieve higher power output, the device was epi-side-down mounted on the diamond heatsink with indium and cleaved into chips of 4mm, and the back facet was high-reflectance(HR) coated with Al2O3/Ti/Au/Ti/Al2O3. After installing the thermistor, the laser was fixed on the water cooling platform with thermoelectric cooler (TEC) for temperature control, and the output light is directly measured by the pyroelectric power meter (Molectron, EPM1000) without lens collimation. The power-current-voltage (P-I-V) characteristics and WPE as function of current of a 4mm×8µm (cavity length × ridge width) HR coated QCL at different temperature in continuous-wave and pulsed operation are shown in Fig. 4(a) and Fig. 4(c), respectively. The maximum WPE and the maximum peak power in pulsed mode was obtained to 13.5% and 2.3W at 293K. We also analyzed the characteristic temperature of the device based on the pulsed P-I-V test results. As shown in Fig. 4(b), the characteristic temperature of T0 and T1 were 151K and 290K, respectively. Furthermore, we also simulated the junction temperature of the device in CW mode operation, the junction temperature was calculated to be 381K, with the heatsink temperature of 303K and power injection of 13.12W (corresponding to the maximum power injection of the device in CW operation under 303K). It's worth noting that our pulse power supply does not match well with the device, so the optical power measured under the set duty cycle is lower than it actually is.

 figure: Fig. 4.

Fig. 4. (a) The P-I-V and WPE experimental results at different temperature and (b). characteristic temperatures fitting of a cavity length 4mm, 8µm ridge wide, HR-coated, epi-down device in pulsed operation with duty cycle of 2%. Inset in (a): pulsed emitting spectrum. (c). The P-I-V and WPE experimental results at different temperature in CW operation. Inset in (c): CW laser spectrum at a current of 0.6 A at 293K under water and TEC cooling. (d) The P-I results of uncoated device at different cavity length in pulsed mode. Inset in (d): Inverse external quantum efficiency as a function of cavity length L.

Download Full Size | PPT Slide | PDF

To prevent the device from burning out, we did not add the current to the roll-over. A maximum CW optical output power of 1.17W, a threshold current density (Jth) of only 1.09 kA/cm2 were measured at 293 K, and the maximum power still reached 950mW at 313K. The maximum WPE of 9.08% was also measured at 293K under a current of 0.85A and a little lower than that reported in Ref 1, which was mainly due to the fact that we did not have the process of proper AR coatings in the front cavity facet (Al2O3/Ge AR coatings we have mastered may absorb light of long-wave infrared, and are prone to disaster under high output power), and in order to ensure the optical power efficiency, the cavity length of the device could not be further increased. Besides, emission spectrum of QCL at 293K measured through Fourier transform infrared (FTIR) spectrometer was shown in the inset of Fig. 4(a), giving a central wavelength 7.7 µm at a current of 0.6 A. There were no AR coatings for the device, so the low threshold current was partly related to the small mirror loss αm∼0.42cm−1. Besides, P-I measurement results of uncoated devices with cavity length of 4mm,6mm,8mm were shown in Fig. 4. (d), giving the internal efficiency ηi of 64.1% and waveguide loss αw of 1.18cm−1 as inset of Fig. 4. (d) shown, which contributed to the low Jth.

By constructing the external-cavity quantum cascade laser (EC-QCL) system of Littrow, we obtained the spectra and peak output power under different blazed grating angles as shown in the Fig. 5., the device was fabricated to 4mm and emitting on both sides with only the front facet AR(Al2O3/Ge) coated for higher external cavity feedback. The results showed a broad tuning range from 1396.2cm−1 (λ=7.16µm) to 1226cm−1 (λ=8.16µm) covering all the CH4 molecular absorption spectral lines in 7.2-8.1µm. Good tuning performance of the EC-QCL comes from the broad gain of BTC active structure, good optical collimation, the high collection efficiency of lens and high diffraction efficiency of blazed gratings. The maximum peak output power collected from the back facet (collimated through lens) of the 4mm external cavity tunable laser was 221mW corresponding to an emitting wavelength of 7.67µm (1302.98cm−1), under the duty cycle of 2%(10kHz,2us) and current of 600mA. The average output power was 505mW at equal emitting wavelength when the current increased to 800mA.

 figure: Fig. 5.

Fig. 5. Tuning behavior and peak power of the EC-QCL of the device. Measurements were taken at room temperature with a duty cycle of 2% (10kHz,2 us) at 0.6A.

Download Full Size | PPT Slide | PDF

The beam picture of the laser at pumping current slightly above threshold is shown in shown in Fig. 6. The picture was taken with a pyroelectric camera placed 25cm away from the laser, with lens(Lightpath,390037IR1) collimation. The beam consisted of a pure zero order mode TM00 even when the current was increased to 1 A, which confirmed that the 8 µm-wide of the ridge was suitable to prevent higher-order transverse modes from lasing.

 figure: Fig. 6.

Fig. 6. The beam picture of the QCL measured in pulsed mode at room temperature under a current of 0.5 A with a duty cycle of 8%(40KHz 2us), The horizontal and vertical beam sizes are 2.71mm and 2.26mm, respectively.

Download Full Size | PPT Slide | PDF

5. Conclusion

In conclusion, we demonstrate 9.08% WPE and 1.17W output power of a 7.7 µm HR-coated QCL in CW operation at 293K. The maximum WPE and the maximum peak power in pulsed mode at 293K were measured to 13.5% and 2.3W, respectively. The device used bound-to-continuum design, strain-balanced active region and low voltage of 96meV for achieving higher WPE. Ns of 50 and 4.5µm of both InP cladding and buffer layer had also been utilized, giving a low αw of 1.18cm−1 contributing to the high WPE and low Jth of 1.09 kA/cm2 in CW mode. We believe that the maximum WPE in CW mode can exceed the previous result (10%) reported in Ref 1 by more proper AR coatings on the front facet, and the maximum output power will be higher by increasing the cavity length. Finally, a broad EC-QCL tuning range from 7.16µm to 8.16µm and peak power of 221mW were reported, which were friendly to trace gas sensing for CH4 and N2O.

Funding

National Key Research and Development Program of China (2018YFA0209103, 2018YFB2200504); National Natural Science Foundation of China (61674144, 61774146, 61774150, 61790583, 61991430); Chinese Academy of Sciences Key Project (2018147, QYZDJ-SSW-JSC027, XDB43000000, YJKYYQ20190002).

Acknowledgments

The authors would like to thank Ping Liang and Ying Hu for their help in device processing.

Disclosures

The authors declare no conflicts of interest.

References

1. R. Maulini, A. Lyakh, A. Tsekoun, C. Kumar, and N. Patelet, “λ∼ 7.1 µm quantum cascade lasers with 19% wall-plug efficiency at room temperature,” Opt. Express 19(18), 17203–17211 (2011). [CrossRef]  

2. I. Mappé, L. Joly, G. Durry, X. Thomas, T. Decarpenterie, J. Cousin, N. Dumelie, E. Roth, A. Chakir, and P. G. Grillon, “A quantum cascade laser absorption spectrometer devoted to the in situ measurement of atmospheric N2O and CH4 emission fluxes,” Rev. Sci. Instrum. 84(2), 023103 (2013). [CrossRef]  

3. J. Hodgkinson and P. Tatam R, “Optical gas sensing: a review,” Meas. Sci. Technol. 24(1), 012004 (2013). [CrossRef]  

4. J. Sun, H. Deng, N. W. Liu, H. L. Wang, B. L. Yu, and J. S. Li, “Mid-infrared gas absorption sensor based on a broadband external cavity quantum cascade laser,” Rev. Sci. Instrum. 87(12), 123101 (2016). [CrossRef]  

5. J Faist, Quantum cascade lasers (OUP Oxford, 2013).

6. F. Wang, S. Slivken, D. H. Wu, and M. Razeghi, “Room temperature quantum cascade lasers with 22% wall plug efficiency in continuous-wave operation,” Opt. Express 28(12), 17532–17538 (2020). [CrossRef]  

7. M. Razeghi, “High-performance InP-based mid-IR quantum cascade lasers,” IEEE J. Sel. Top. Quantum Electron. 15(3), 941–951 (2009). [CrossRef]  

8. Q. K. Yang, C. Schilling, R. Ostendorf, S. Hugger, F. Fuchs, and J. Wagner, “Wall-plug efficiency of mid-infrared quantum cascade lasers,” J. Appl. Phys. 111(5), 053111 (2012). [CrossRef]  

9. M. Troccoli, A. Lyakh, J. Fan, X. J. Wang, R. Maulini, A. G. Tsekoun, G. Rowel, C. Kumar, and N. Patel, “Long-Wave IR Quantum Cascade Lasers for emission in the λ = 8-12µm spectral region,” Opt. Mater. Express 3(9), 1546–1560 (2013). [CrossRef]  

10. M. Razeghi, W. Zhou, S. Slivken, Q. Y. Lu, D. Wu, and R. McClintock, “Recent progress of quantum cascade laser research from 3 to 12 µm at the Center for Quantum Devices,” Appl. Opt. 56(31), H30–H44 (2017). [CrossRef]  

11. A. Lyakh, R. Maulini, A. Tsekoun, G. Rowel, and C. Kumar N. Patel, “Multiwatt long wavelength quantum cascade lasers based on high strain composition with 70% injection efficiency,” Opt. Express 20(22), 24272–24279 (2012). [CrossRef]  

12. F. Xie F, C. Caneau, H. P. Leblanc, D. P. Caffey, L. C. Hughes, T. Day, and C.-e. Zah, “Watt-level room temperature continuous-wave operation of quantum cascade lasers with λ> 10 µm[J],” IEEE J. Sel. Top. Quantum Electron. 19(4), 1200407 (2013). [CrossRef]  

13. N. Bandyopadhyay, Y. Bai Y, S. Slivken, and M. Razeghi, “High power operation of λ∼ 5.2–11 µm strain balanced quantum cascade lasers based on the same material composition,” Appl. Phys. Lett. 105(7), 071106 (2014). [CrossRef]  

14. X. Huang X, W. O. Charles, and C. Gmachl, “Temperature-insensitive long-wavelength (λ≈ 14 µm) Quantum Cascade lasers with low threshold,” Opt. Express 19(9), 8297–8302 (2011). [CrossRef]  

15. S. Z. Niu, J. Q. Liu, F. M. Cheng, H. Wang, J. C. Zhang, N. Zhuo, S. Q. Zhai, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, X. H. Wang, and Z. P. Wei, “14 µm quantum cascade lasers based on diagonal transition and nonresonant extraction,” Photonics Res. 7(11), 1244–1248 (2019). [CrossRef]  

16. M. Troccoli, X. Wang, and J. Fan, “Quantum cascade lasers: high-power emission and single-mode operation in the long-wave infrared (> 6 µm),” Opt. Eng. 49(11), 111106 (2010). [CrossRef]  

17. R. P. Leavitt, J. L. Bradshaw, K. M. Lascola, M. Gregory P, M. Frankie, T. Frederick J, and P. John T, “High-performance quantum cascade lasers in the 7.3-to 7.8-µm wavelength band using strained active regions,” Opt. Eng. 49(11), 111109 (2010). [CrossRef]  

18. W. Zhou, Q. Y. Lu, D. H. Wu, S. Slivken, and M. Razeghi, “High-power, continuous-wave, phase-locked quantum cascade laser arrays emitting at 8 µm,” Opt. Express 27(11), 15776–15785 (2019). [CrossRef]  

19. D. Botez, J. D. Kirch, C. Boyle, K. M. Oresick, C. Sigler, H. Kim, B. B. Knipfer, J. H. Ryu, D. Lindberg, T. Earles, L. J. Mawst, and Y. V. Flores, “High-efficiency, high-power mid-infrared quantum cascade lasers,” Opt. Mater. Express 8(5), 1378–1398 (2018). [CrossRef]  

20. J. D. Kirch, C.-C. Chang, C. Boyle, L. J. Mawst, D. Lindberg, T. Earles, and D. Botez, “86% internal differential efficiency from 8 to 9 µm-emitting, step-taper active-region quantum cascade lasers,” Opt. Express 24(21), 24483–24494 (2016). [CrossRef]  

21. D. Botez, C.-C. Chang, and L. J. Mawst, “Temperature sensitivity of the electro-optical characteristics for midinfrared (λ = 3–16 µm)-emitting quantum cascade lasers,” J. Phys. D: Appl. Phys. 49(4), 043001 (2016). [CrossRef]  

22. S. Z. Niu, J. Q. Liu, Y. Zhao, F. M. Cheng, J. C. Zhang, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, Z. P. Wei, and X. H. Wang, “High-Performance Bound-to-Continuum Quantum Cascade Lasers at λ∼ 8 µm,” J. Nanosci. Nanotechnol. 18(11), 7498–7501 (2018). [CrossRef]  

23. R Maulini, A Lyakh, A Tsekoun, R. Go, C. Pflüg, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett. 95(15), 151112 (2009). [CrossRef]  

References

  • View by:

  1. R. Maulini, A. Lyakh, A. Tsekoun, C. Kumar, and N. Patelet, “λ∼ 7.1 µm quantum cascade lasers with 19% wall-plug efficiency at room temperature,” Opt. Express 19(18), 17203–17211 (2011).
    [Crossref]
  2. I. Mappé, L. Joly, G. Durry, X. Thomas, T. Decarpenterie, J. Cousin, N. Dumelie, E. Roth, A. Chakir, and P. G. Grillon, “A quantum cascade laser absorption spectrometer devoted to the in situ measurement of atmospheric N2O and CH4 emission fluxes,” Rev. Sci. Instrum. 84(2), 023103 (2013).
    [Crossref]
  3. J. Hodgkinson and P. Tatam R, “Optical gas sensing: a review,” Meas. Sci. Technol. 24(1), 012004 (2013).
    [Crossref]
  4. J. Sun, H. Deng, N. W. Liu, H. L. Wang, B. L. Yu, and J. S. Li, “Mid-infrared gas absorption sensor based on a broadband external cavity quantum cascade laser,” Rev. Sci. Instrum. 87(12), 123101 (2016).
    [Crossref]
  5. J Faist, Quantum cascade lasers (OUP Oxford, 2013).
  6. F. Wang, S. Slivken, D. H. Wu, and M. Razeghi, “Room temperature quantum cascade lasers with 22% wall plug efficiency in continuous-wave operation,” Opt. Express 28(12), 17532–17538 (2020).
    [Crossref]
  7. M. Razeghi, “High-performance InP-based mid-IR quantum cascade lasers,” IEEE J. Sel. Top. Quantum Electron. 15(3), 941–951 (2009).
    [Crossref]
  8. Q. K. Yang, C. Schilling, R. Ostendorf, S. Hugger, F. Fuchs, and J. Wagner, “Wall-plug efficiency of mid-infrared quantum cascade lasers,” J. Appl. Phys. 111(5), 053111 (2012).
    [Crossref]
  9. M. Troccoli, A. Lyakh, J. Fan, X. J. Wang, R. Maulini, A. G. Tsekoun, G. Rowel, C. Kumar, and N. Patel, “Long-Wave IR Quantum Cascade Lasers for emission in the λ = 8-12µm spectral region,” Opt. Mater. Express 3(9), 1546–1560 (2013).
    [Crossref]
  10. M. Razeghi, W. Zhou, S. Slivken, Q. Y. Lu, D. Wu, and R. McClintock, “Recent progress of quantum cascade laser research from 3 to 12 µm at the Center for Quantum Devices,” Appl. Opt. 56(31), H30–H44 (2017).
    [Crossref]
  11. A. Lyakh, R. Maulini, A. Tsekoun, G. Rowel, and C. Kumar N. Patel, “Multiwatt long wavelength quantum cascade lasers based on high strain composition with 70% injection efficiency,” Opt. Express 20(22), 24272–24279 (2012).
    [Crossref]
  12. F. Xie F, C. Caneau, H. P. Leblanc, D. P. Caffey, L. C. Hughes, T. Day, and C.-e. Zah, “Watt-level room temperature continuous-wave operation of quantum cascade lasers with λ> 10 µm[J],” IEEE J. Sel. Top. Quantum Electron. 19(4), 1200407 (2013).
    [Crossref]
  13. N. Bandyopadhyay, Y. Bai Y, S. Slivken, and M. Razeghi, “High power operation of λ∼ 5.2–11 µm strain balanced quantum cascade lasers based on the same material composition,” Appl. Phys. Lett. 105(7), 071106 (2014).
    [Crossref]
  14. X. Huang X, W. O. Charles, and C. Gmachl, “Temperature-insensitive long-wavelength (λ≈ 14 µm) Quantum Cascade lasers with low threshold,” Opt. Express 19(9), 8297–8302 (2011).
    [Crossref]
  15. S. Z. Niu, J. Q. Liu, F. M. Cheng, H. Wang, J. C. Zhang, N. Zhuo, S. Q. Zhai, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, X. H. Wang, and Z. P. Wei, “14 µm quantum cascade lasers based on diagonal transition and nonresonant extraction,” Photonics Res. 7(11), 1244–1248 (2019).
    [Crossref]
  16. M. Troccoli, X. Wang, and J. Fan, “Quantum cascade lasers: high-power emission and single-mode operation in the long-wave infrared (> 6 µm),” Opt. Eng. 49(11), 111106 (2010).
    [Crossref]
  17. R. P. Leavitt, J. L. Bradshaw, K. M. Lascola, M. Gregory P, M. Frankie, T. Frederick J, and P. John T, “High-performance quantum cascade lasers in the 7.3-to 7.8-µm wavelength band using strained active regions,” Opt. Eng. 49(11), 111109 (2010).
    [Crossref]
  18. W. Zhou, Q. Y. Lu, D. H. Wu, S. Slivken, and M. Razeghi, “High-power, continuous-wave, phase-locked quantum cascade laser arrays emitting at 8 µm,” Opt. Express 27(11), 15776–15785 (2019).
    [Crossref]
  19. D. Botez, J. D. Kirch, C. Boyle, K. M. Oresick, C. Sigler, H. Kim, B. B. Knipfer, J. H. Ryu, D. Lindberg, T. Earles, L. J. Mawst, and Y. V. Flores, “High-efficiency, high-power mid-infrared quantum cascade lasers,” Opt. Mater. Express 8(5), 1378–1398 (2018).
    [Crossref]
  20. J. D. Kirch, C.-C. Chang, C. Boyle, L. J. Mawst, D. Lindberg, T. Earles, and D. Botez, “86% internal differential efficiency from 8 to 9 µm-emitting, step-taper active-region quantum cascade lasers,” Opt. Express 24(21), 24483–24494 (2016).
    [Crossref]
  21. D. Botez, C.-C. Chang, and L. J. Mawst, “Temperature sensitivity of the electro-optical characteristics for midinfrared (λ = 3–16 µm)-emitting quantum cascade lasers,” J. Phys. D: Appl. Phys. 49(4), 043001 (2016).
    [Crossref]
  22. S. Z. Niu, J. Q. Liu, Y. Zhao, F. M. Cheng, J. C. Zhang, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, Z. P. Wei, and X. H. Wang, “High-Performance Bound-to-Continuum Quantum Cascade Lasers at λ∼ 8 µm,” J. Nanosci. Nanotechnol. 18(11), 7498–7501 (2018).
    [Crossref]
  23. R Maulini, A Lyakh, A Tsekoun, R. Go, C. Pflüg, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett. 95(15), 151112 (2009).
    [Crossref]

2020 (1)

2019 (2)

W. Zhou, Q. Y. Lu, D. H. Wu, S. Slivken, and M. Razeghi, “High-power, continuous-wave, phase-locked quantum cascade laser arrays emitting at 8 µm,” Opt. Express 27(11), 15776–15785 (2019).
[Crossref]

S. Z. Niu, J. Q. Liu, F. M. Cheng, H. Wang, J. C. Zhang, N. Zhuo, S. Q. Zhai, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, X. H. Wang, and Z. P. Wei, “14 µm quantum cascade lasers based on diagonal transition and nonresonant extraction,” Photonics Res. 7(11), 1244–1248 (2019).
[Crossref]

2018 (2)

S. Z. Niu, J. Q. Liu, Y. Zhao, F. M. Cheng, J. C. Zhang, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, Z. P. Wei, and X. H. Wang, “High-Performance Bound-to-Continuum Quantum Cascade Lasers at λ∼ 8 µm,” J. Nanosci. Nanotechnol. 18(11), 7498–7501 (2018).
[Crossref]

D. Botez, J. D. Kirch, C. Boyle, K. M. Oresick, C. Sigler, H. Kim, B. B. Knipfer, J. H. Ryu, D. Lindberg, T. Earles, L. J. Mawst, and Y. V. Flores, “High-efficiency, high-power mid-infrared quantum cascade lasers,” Opt. Mater. Express 8(5), 1378–1398 (2018).
[Crossref]

2017 (1)

2016 (3)

J. D. Kirch, C.-C. Chang, C. Boyle, L. J. Mawst, D. Lindberg, T. Earles, and D. Botez, “86% internal differential efficiency from 8 to 9 µm-emitting, step-taper active-region quantum cascade lasers,” Opt. Express 24(21), 24483–24494 (2016).
[Crossref]

D. Botez, C.-C. Chang, and L. J. Mawst, “Temperature sensitivity of the electro-optical characteristics for midinfrared (λ = 3–16 µm)-emitting quantum cascade lasers,” J. Phys. D: Appl. Phys. 49(4), 043001 (2016).
[Crossref]

J. Sun, H. Deng, N. W. Liu, H. L. Wang, B. L. Yu, and J. S. Li, “Mid-infrared gas absorption sensor based on a broadband external cavity quantum cascade laser,” Rev. Sci. Instrum. 87(12), 123101 (2016).
[Crossref]

2014 (1)

N. Bandyopadhyay, Y. Bai Y, S. Slivken, and M. Razeghi, “High power operation of λ∼ 5.2–11 µm strain balanced quantum cascade lasers based on the same material composition,” Appl. Phys. Lett. 105(7), 071106 (2014).
[Crossref]

2013 (4)

I. Mappé, L. Joly, G. Durry, X. Thomas, T. Decarpenterie, J. Cousin, N. Dumelie, E. Roth, A. Chakir, and P. G. Grillon, “A quantum cascade laser absorption spectrometer devoted to the in situ measurement of atmospheric N2O and CH4 emission fluxes,” Rev. Sci. Instrum. 84(2), 023103 (2013).
[Crossref]

J. Hodgkinson and P. Tatam R, “Optical gas sensing: a review,” Meas. Sci. Technol. 24(1), 012004 (2013).
[Crossref]

M. Troccoli, A. Lyakh, J. Fan, X. J. Wang, R. Maulini, A. G. Tsekoun, G. Rowel, C. Kumar, and N. Patel, “Long-Wave IR Quantum Cascade Lasers for emission in the λ = 8-12µm spectral region,” Opt. Mater. Express 3(9), 1546–1560 (2013).
[Crossref]

F. Xie F, C. Caneau, H. P. Leblanc, D. P. Caffey, L. C. Hughes, T. Day, and C.-e. Zah, “Watt-level room temperature continuous-wave operation of quantum cascade lasers with λ> 10 µm[J],” IEEE J. Sel. Top. Quantum Electron. 19(4), 1200407 (2013).
[Crossref]

2012 (2)

Q. K. Yang, C. Schilling, R. Ostendorf, S. Hugger, F. Fuchs, and J. Wagner, “Wall-plug efficiency of mid-infrared quantum cascade lasers,” J. Appl. Phys. 111(5), 053111 (2012).
[Crossref]

A. Lyakh, R. Maulini, A. Tsekoun, G. Rowel, and C. Kumar N. Patel, “Multiwatt long wavelength quantum cascade lasers based on high strain composition with 70% injection efficiency,” Opt. Express 20(22), 24272–24279 (2012).
[Crossref]

2011 (2)

2010 (2)

M. Troccoli, X. Wang, and J. Fan, “Quantum cascade lasers: high-power emission and single-mode operation in the long-wave infrared (> 6 µm),” Opt. Eng. 49(11), 111106 (2010).
[Crossref]

R. P. Leavitt, J. L. Bradshaw, K. M. Lascola, M. Gregory P, M. Frankie, T. Frederick J, and P. John T, “High-performance quantum cascade lasers in the 7.3-to 7.8-µm wavelength band using strained active regions,” Opt. Eng. 49(11), 111109 (2010).
[Crossref]

2009 (2)

R Maulini, A Lyakh, A Tsekoun, R. Go, C. Pflüg, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett. 95(15), 151112 (2009).
[Crossref]

M. Razeghi, “High-performance InP-based mid-IR quantum cascade lasers,” IEEE J. Sel. Top. Quantum Electron. 15(3), 941–951 (2009).
[Crossref]

Bai Y, Y.

N. Bandyopadhyay, Y. Bai Y, S. Slivken, and M. Razeghi, “High power operation of λ∼ 5.2–11 µm strain balanced quantum cascade lasers based on the same material composition,” Appl. Phys. Lett. 105(7), 071106 (2014).
[Crossref]

Bandyopadhyay, N.

N. Bandyopadhyay, Y. Bai Y, S. Slivken, and M. Razeghi, “High power operation of λ∼ 5.2–11 µm strain balanced quantum cascade lasers based on the same material composition,” Appl. Phys. Lett. 105(7), 071106 (2014).
[Crossref]

Botez, D.

Boyle, C.

Bradshaw, J. L.

R. P. Leavitt, J. L. Bradshaw, K. M. Lascola, M. Gregory P, M. Frankie, T. Frederick J, and P. John T, “High-performance quantum cascade lasers in the 7.3-to 7.8-µm wavelength band using strained active regions,” Opt. Eng. 49(11), 111109 (2010).
[Crossref]

Caffey, D. P.

F. Xie F, C. Caneau, H. P. Leblanc, D. P. Caffey, L. C. Hughes, T. Day, and C.-e. Zah, “Watt-level room temperature continuous-wave operation of quantum cascade lasers with λ> 10 µm[J],” IEEE J. Sel. Top. Quantum Electron. 19(4), 1200407 (2013).
[Crossref]

Caneau, C.

F. Xie F, C. Caneau, H. P. Leblanc, D. P. Caffey, L. C. Hughes, T. Day, and C.-e. Zah, “Watt-level room temperature continuous-wave operation of quantum cascade lasers with λ> 10 µm[J],” IEEE J. Sel. Top. Quantum Electron. 19(4), 1200407 (2013).
[Crossref]

Capasso, F.

R Maulini, A Lyakh, A Tsekoun, R. Go, C. Pflüg, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett. 95(15), 151112 (2009).
[Crossref]

Chakir, A.

I. Mappé, L. Joly, G. Durry, X. Thomas, T. Decarpenterie, J. Cousin, N. Dumelie, E. Roth, A. Chakir, and P. G. Grillon, “A quantum cascade laser absorption spectrometer devoted to the in situ measurement of atmospheric N2O and CH4 emission fluxes,” Rev. Sci. Instrum. 84(2), 023103 (2013).
[Crossref]

Chang, C.-C.

J. D. Kirch, C.-C. Chang, C. Boyle, L. J. Mawst, D. Lindberg, T. Earles, and D. Botez, “86% internal differential efficiency from 8 to 9 µm-emitting, step-taper active-region quantum cascade lasers,” Opt. Express 24(21), 24483–24494 (2016).
[Crossref]

D. Botez, C.-C. Chang, and L. J. Mawst, “Temperature sensitivity of the electro-optical characteristics for midinfrared (λ = 3–16 µm)-emitting quantum cascade lasers,” J. Phys. D: Appl. Phys. 49(4), 043001 (2016).
[Crossref]

Charles, W. O.

Cheng, F. M.

S. Z. Niu, J. Q. Liu, F. M. Cheng, H. Wang, J. C. Zhang, N. Zhuo, S. Q. Zhai, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, X. H. Wang, and Z. P. Wei, “14 µm quantum cascade lasers based on diagonal transition and nonresonant extraction,” Photonics Res. 7(11), 1244–1248 (2019).
[Crossref]

S. Z. Niu, J. Q. Liu, Y. Zhao, F. M. Cheng, J. C. Zhang, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, Z. P. Wei, and X. H. Wang, “High-Performance Bound-to-Continuum Quantum Cascade Lasers at λ∼ 8 µm,” J. Nanosci. Nanotechnol. 18(11), 7498–7501 (2018).
[Crossref]

Cousin, J.

I. Mappé, L. Joly, G. Durry, X. Thomas, T. Decarpenterie, J. Cousin, N. Dumelie, E. Roth, A. Chakir, and P. G. Grillon, “A quantum cascade laser absorption spectrometer devoted to the in situ measurement of atmospheric N2O and CH4 emission fluxes,” Rev. Sci. Instrum. 84(2), 023103 (2013).
[Crossref]

Day, T.

F. Xie F, C. Caneau, H. P. Leblanc, D. P. Caffey, L. C. Hughes, T. Day, and C.-e. Zah, “Watt-level room temperature continuous-wave operation of quantum cascade lasers with λ> 10 µm[J],” IEEE J. Sel. Top. Quantum Electron. 19(4), 1200407 (2013).
[Crossref]

Decarpenterie, T.

I. Mappé, L. Joly, G. Durry, X. Thomas, T. Decarpenterie, J. Cousin, N. Dumelie, E. Roth, A. Chakir, and P. G. Grillon, “A quantum cascade laser absorption spectrometer devoted to the in situ measurement of atmospheric N2O and CH4 emission fluxes,” Rev. Sci. Instrum. 84(2), 023103 (2013).
[Crossref]

Deng, H.

J. Sun, H. Deng, N. W. Liu, H. L. Wang, B. L. Yu, and J. S. Li, “Mid-infrared gas absorption sensor based on a broadband external cavity quantum cascade laser,” Rev. Sci. Instrum. 87(12), 123101 (2016).
[Crossref]

Diehl, L.

R Maulini, A Lyakh, A Tsekoun, R. Go, C. Pflüg, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett. 95(15), 151112 (2009).
[Crossref]

Dumelie, N.

I. Mappé, L. Joly, G. Durry, X. Thomas, T. Decarpenterie, J. Cousin, N. Dumelie, E. Roth, A. Chakir, and P. G. Grillon, “A quantum cascade laser absorption spectrometer devoted to the in situ measurement of atmospheric N2O and CH4 emission fluxes,” Rev. Sci. Instrum. 84(2), 023103 (2013).
[Crossref]

Durry, G.

I. Mappé, L. Joly, G. Durry, X. Thomas, T. Decarpenterie, J. Cousin, N. Dumelie, E. Roth, A. Chakir, and P. G. Grillon, “A quantum cascade laser absorption spectrometer devoted to the in situ measurement of atmospheric N2O and CH4 emission fluxes,” Rev. Sci. Instrum. 84(2), 023103 (2013).
[Crossref]

Earles, T.

Faist, J

J Faist, Quantum cascade lasers (OUP Oxford, 2013).

Fan, J.

M. Troccoli, A. Lyakh, J. Fan, X. J. Wang, R. Maulini, A. G. Tsekoun, G. Rowel, C. Kumar, and N. Patel, “Long-Wave IR Quantum Cascade Lasers for emission in the λ = 8-12µm spectral region,” Opt. Mater. Express 3(9), 1546–1560 (2013).
[Crossref]

M. Troccoli, X. Wang, and J. Fan, “Quantum cascade lasers: high-power emission and single-mode operation in the long-wave infrared (> 6 µm),” Opt. Eng. 49(11), 111106 (2010).
[Crossref]

Flores, Y. V.

Frankie, M.

R. P. Leavitt, J. L. Bradshaw, K. M. Lascola, M. Gregory P, M. Frankie, T. Frederick J, and P. John T, “High-performance quantum cascade lasers in the 7.3-to 7.8-µm wavelength band using strained active regions,” Opt. Eng. 49(11), 111109 (2010).
[Crossref]

Frederick J, T.

R. P. Leavitt, J. L. Bradshaw, K. M. Lascola, M. Gregory P, M. Frankie, T. Frederick J, and P. John T, “High-performance quantum cascade lasers in the 7.3-to 7.8-µm wavelength band using strained active regions,” Opt. Eng. 49(11), 111109 (2010).
[Crossref]

Fuchs, F.

Q. K. Yang, C. Schilling, R. Ostendorf, S. Hugger, F. Fuchs, and J. Wagner, “Wall-plug efficiency of mid-infrared quantum cascade lasers,” J. Appl. Phys. 111(5), 053111 (2012).
[Crossref]

Gmachl, C.

Go, R.

R Maulini, A Lyakh, A Tsekoun, R. Go, C. Pflüg, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett. 95(15), 151112 (2009).
[Crossref]

Gregory P, M.

R. P. Leavitt, J. L. Bradshaw, K. M. Lascola, M. Gregory P, M. Frankie, T. Frederick J, and P. John T, “High-performance quantum cascade lasers in the 7.3-to 7.8-µm wavelength band using strained active regions,” Opt. Eng. 49(11), 111109 (2010).
[Crossref]

Grillon, P. G.

I. Mappé, L. Joly, G. Durry, X. Thomas, T. Decarpenterie, J. Cousin, N. Dumelie, E. Roth, A. Chakir, and P. G. Grillon, “A quantum cascade laser absorption spectrometer devoted to the in situ measurement of atmospheric N2O and CH4 emission fluxes,” Rev. Sci. Instrum. 84(2), 023103 (2013).
[Crossref]

Hodgkinson, J.

J. Hodgkinson and P. Tatam R, “Optical gas sensing: a review,” Meas. Sci. Technol. 24(1), 012004 (2013).
[Crossref]

Huang X, X.

Hugger, S.

Q. K. Yang, C. Schilling, R. Ostendorf, S. Hugger, F. Fuchs, and J. Wagner, “Wall-plug efficiency of mid-infrared quantum cascade lasers,” J. Appl. Phys. 111(5), 053111 (2012).
[Crossref]

Hughes, L. C.

F. Xie F, C. Caneau, H. P. Leblanc, D. P. Caffey, L. C. Hughes, T. Day, and C.-e. Zah, “Watt-level room temperature continuous-wave operation of quantum cascade lasers with λ> 10 µm[J],” IEEE J. Sel. Top. Quantum Electron. 19(4), 1200407 (2013).
[Crossref]

John T, P.

R. P. Leavitt, J. L. Bradshaw, K. M. Lascola, M. Gregory P, M. Frankie, T. Frederick J, and P. John T, “High-performance quantum cascade lasers in the 7.3-to 7.8-µm wavelength band using strained active regions,” Opt. Eng. 49(11), 111109 (2010).
[Crossref]

Joly, L.

I. Mappé, L. Joly, G. Durry, X. Thomas, T. Decarpenterie, J. Cousin, N. Dumelie, E. Roth, A. Chakir, and P. G. Grillon, “A quantum cascade laser absorption spectrometer devoted to the in situ measurement of atmospheric N2O and CH4 emission fluxes,” Rev. Sci. Instrum. 84(2), 023103 (2013).
[Crossref]

Kim, H.

Kirch, J. D.

Knipfer, B. B.

Kumar, C.

Kumar N. Patel, C.

Lascola, K. M.

R. P. Leavitt, J. L. Bradshaw, K. M. Lascola, M. Gregory P, M. Frankie, T. Frederick J, and P. John T, “High-performance quantum cascade lasers in the 7.3-to 7.8-µm wavelength band using strained active regions,” Opt. Eng. 49(11), 111109 (2010).
[Crossref]

Leavitt, R. P.

R. P. Leavitt, J. L. Bradshaw, K. M. Lascola, M. Gregory P, M. Frankie, T. Frederick J, and P. John T, “High-performance quantum cascade lasers in the 7.3-to 7.8-µm wavelength band using strained active regions,” Opt. Eng. 49(11), 111109 (2010).
[Crossref]

Leblanc, H. P.

F. Xie F, C. Caneau, H. P. Leblanc, D. P. Caffey, L. C. Hughes, T. Day, and C.-e. Zah, “Watt-level room temperature continuous-wave operation of quantum cascade lasers with λ> 10 µm[J],” IEEE J. Sel. Top. Quantum Electron. 19(4), 1200407 (2013).
[Crossref]

Li, J. S.

J. Sun, H. Deng, N. W. Liu, H. L. Wang, B. L. Yu, and J. S. Li, “Mid-infrared gas absorption sensor based on a broadband external cavity quantum cascade laser,” Rev. Sci. Instrum. 87(12), 123101 (2016).
[Crossref]

Lindberg, D.

Liu, F. Q.

S. Z. Niu, J. Q. Liu, F. M. Cheng, H. Wang, J. C. Zhang, N. Zhuo, S. Q. Zhai, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, X. H. Wang, and Z. P. Wei, “14 µm quantum cascade lasers based on diagonal transition and nonresonant extraction,” Photonics Res. 7(11), 1244–1248 (2019).
[Crossref]

S. Z. Niu, J. Q. Liu, Y. Zhao, F. M. Cheng, J. C. Zhang, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, Z. P. Wei, and X. H. Wang, “High-Performance Bound-to-Continuum Quantum Cascade Lasers at λ∼ 8 µm,” J. Nanosci. Nanotechnol. 18(11), 7498–7501 (2018).
[Crossref]

Liu, J. Q.

S. Z. Niu, J. Q. Liu, F. M. Cheng, H. Wang, J. C. Zhang, N. Zhuo, S. Q. Zhai, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, X. H. Wang, and Z. P. Wei, “14 µm quantum cascade lasers based on diagonal transition and nonresonant extraction,” Photonics Res. 7(11), 1244–1248 (2019).
[Crossref]

S. Z. Niu, J. Q. Liu, Y. Zhao, F. M. Cheng, J. C. Zhang, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, Z. P. Wei, and X. H. Wang, “High-Performance Bound-to-Continuum Quantum Cascade Lasers at λ∼ 8 µm,” J. Nanosci. Nanotechnol. 18(11), 7498–7501 (2018).
[Crossref]

Liu, N. W.

J. Sun, H. Deng, N. W. Liu, H. L. Wang, B. L. Yu, and J. S. Li, “Mid-infrared gas absorption sensor based on a broadband external cavity quantum cascade laser,” Rev. Sci. Instrum. 87(12), 123101 (2016).
[Crossref]

Liu, S. M.

S. Z. Niu, J. Q. Liu, F. M. Cheng, H. Wang, J. C. Zhang, N. Zhuo, S. Q. Zhai, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, X. H. Wang, and Z. P. Wei, “14 µm quantum cascade lasers based on diagonal transition and nonresonant extraction,” Photonics Res. 7(11), 1244–1248 (2019).
[Crossref]

S. Z. Niu, J. Q. Liu, Y. Zhao, F. M. Cheng, J. C. Zhang, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, Z. P. Wei, and X. H. Wang, “High-Performance Bound-to-Continuum Quantum Cascade Lasers at λ∼ 8 µm,” J. Nanosci. Nanotechnol. 18(11), 7498–7501 (2018).
[Crossref]

Lu, Q. Y.

Lyakh, A

R Maulini, A Lyakh, A Tsekoun, R. Go, C. Pflüg, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett. 95(15), 151112 (2009).
[Crossref]

Lyakh, A.

Mappé, I.

I. Mappé, L. Joly, G. Durry, X. Thomas, T. Decarpenterie, J. Cousin, N. Dumelie, E. Roth, A. Chakir, and P. G. Grillon, “A quantum cascade laser absorption spectrometer devoted to the in situ measurement of atmospheric N2O and CH4 emission fluxes,” Rev. Sci. Instrum. 84(2), 023103 (2013).
[Crossref]

Maulini, R

R Maulini, A Lyakh, A Tsekoun, R. Go, C. Pflüg, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett. 95(15), 151112 (2009).
[Crossref]

Maulini, R.

Mawst, L. J.

McClintock, R.

Niu, S. Z.

S. Z. Niu, J. Q. Liu, F. M. Cheng, H. Wang, J. C. Zhang, N. Zhuo, S. Q. Zhai, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, X. H. Wang, and Z. P. Wei, “14 µm quantum cascade lasers based on diagonal transition and nonresonant extraction,” Photonics Res. 7(11), 1244–1248 (2019).
[Crossref]

S. Z. Niu, J. Q. Liu, Y. Zhao, F. M. Cheng, J. C. Zhang, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, Z. P. Wei, and X. H. Wang, “High-Performance Bound-to-Continuum Quantum Cascade Lasers at λ∼ 8 µm,” J. Nanosci. Nanotechnol. 18(11), 7498–7501 (2018).
[Crossref]

Oresick, K. M.

Ostendorf, R.

Q. K. Yang, C. Schilling, R. Ostendorf, S. Hugger, F. Fuchs, and J. Wagner, “Wall-plug efficiency of mid-infrared quantum cascade lasers,” J. Appl. Phys. 111(5), 053111 (2012).
[Crossref]

Patel, N.

M. Troccoli, A. Lyakh, J. Fan, X. J. Wang, R. Maulini, A. G. Tsekoun, G. Rowel, C. Kumar, and N. Patel, “Long-Wave IR Quantum Cascade Lasers for emission in the λ = 8-12µm spectral region,” Opt. Mater. Express 3(9), 1546–1560 (2013).
[Crossref]

R Maulini, A Lyakh, A Tsekoun, R. Go, C. Pflüg, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett. 95(15), 151112 (2009).
[Crossref]

Patelet, N.

Pflüg, C.

R Maulini, A Lyakh, A Tsekoun, R. Go, C. Pflüg, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett. 95(15), 151112 (2009).
[Crossref]

Razeghi, M.

Roth, E.

I. Mappé, L. Joly, G. Durry, X. Thomas, T. Decarpenterie, J. Cousin, N. Dumelie, E. Roth, A. Chakir, and P. G. Grillon, “A quantum cascade laser absorption spectrometer devoted to the in situ measurement of atmospheric N2O and CH4 emission fluxes,” Rev. Sci. Instrum. 84(2), 023103 (2013).
[Crossref]

Rowel, G.

Ryu, J. H.

Schilling, C.

Q. K. Yang, C. Schilling, R. Ostendorf, S. Hugger, F. Fuchs, and J. Wagner, “Wall-plug efficiency of mid-infrared quantum cascade lasers,” J. Appl. Phys. 111(5), 053111 (2012).
[Crossref]

Sigler, C.

Slivken, S.

Sun, J.

J. Sun, H. Deng, N. W. Liu, H. L. Wang, B. L. Yu, and J. S. Li, “Mid-infrared gas absorption sensor based on a broadband external cavity quantum cascade laser,” Rev. Sci. Instrum. 87(12), 123101 (2016).
[Crossref]

Tatam R, P.

J. Hodgkinson and P. Tatam R, “Optical gas sensing: a review,” Meas. Sci. Technol. 24(1), 012004 (2013).
[Crossref]

Thomas, X.

I. Mappé, L. Joly, G. Durry, X. Thomas, T. Decarpenterie, J. Cousin, N. Dumelie, E. Roth, A. Chakir, and P. G. Grillon, “A quantum cascade laser absorption spectrometer devoted to the in situ measurement of atmospheric N2O and CH4 emission fluxes,” Rev. Sci. Instrum. 84(2), 023103 (2013).
[Crossref]

Troccoli, M.

M. Troccoli, A. Lyakh, J. Fan, X. J. Wang, R. Maulini, A. G. Tsekoun, G. Rowel, C. Kumar, and N. Patel, “Long-Wave IR Quantum Cascade Lasers for emission in the λ = 8-12µm spectral region,” Opt. Mater. Express 3(9), 1546–1560 (2013).
[Crossref]

M. Troccoli, X. Wang, and J. Fan, “Quantum cascade lasers: high-power emission and single-mode operation in the long-wave infrared (> 6 µm),” Opt. Eng. 49(11), 111106 (2010).
[Crossref]

Tsekoun, A

R Maulini, A Lyakh, A Tsekoun, R. Go, C. Pflüg, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett. 95(15), 151112 (2009).
[Crossref]

Tsekoun, A.

Tsekoun, A. G.

Wagner, J.

Q. K. Yang, C. Schilling, R. Ostendorf, S. Hugger, F. Fuchs, and J. Wagner, “Wall-plug efficiency of mid-infrared quantum cascade lasers,” J. Appl. Phys. 111(5), 053111 (2012).
[Crossref]

Wang, F.

Wang, H.

S. Z. Niu, J. Q. Liu, F. M. Cheng, H. Wang, J. C. Zhang, N. Zhuo, S. Q. Zhai, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, X. H. Wang, and Z. P. Wei, “14 µm quantum cascade lasers based on diagonal transition and nonresonant extraction,” Photonics Res. 7(11), 1244–1248 (2019).
[Crossref]

Wang, H. L.

J. Sun, H. Deng, N. W. Liu, H. L. Wang, B. L. Yu, and J. S. Li, “Mid-infrared gas absorption sensor based on a broadband external cavity quantum cascade laser,” Rev. Sci. Instrum. 87(12), 123101 (2016).
[Crossref]

Wang, L. J.

S. Z. Niu, J. Q. Liu, F. M. Cheng, H. Wang, J. C. Zhang, N. Zhuo, S. Q. Zhai, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, X. H. Wang, and Z. P. Wei, “14 µm quantum cascade lasers based on diagonal transition and nonresonant extraction,” Photonics Res. 7(11), 1244–1248 (2019).
[Crossref]

S. Z. Niu, J. Q. Liu, Y. Zhao, F. M. Cheng, J. C. Zhang, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, Z. P. Wei, and X. H. Wang, “High-Performance Bound-to-Continuum Quantum Cascade Lasers at λ∼ 8 µm,” J. Nanosci. Nanotechnol. 18(11), 7498–7501 (2018).
[Crossref]

Wang, X.

M. Troccoli, X. Wang, and J. Fan, “Quantum cascade lasers: high-power emission and single-mode operation in the long-wave infrared (> 6 µm),” Opt. Eng. 49(11), 111106 (2010).
[Crossref]

Wang, X. H.

S. Z. Niu, J. Q. Liu, F. M. Cheng, H. Wang, J. C. Zhang, N. Zhuo, S. Q. Zhai, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, X. H. Wang, and Z. P. Wei, “14 µm quantum cascade lasers based on diagonal transition and nonresonant extraction,” Photonics Res. 7(11), 1244–1248 (2019).
[Crossref]

S. Z. Niu, J. Q. Liu, Y. Zhao, F. M. Cheng, J. C. Zhang, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, Z. P. Wei, and X. H. Wang, “High-Performance Bound-to-Continuum Quantum Cascade Lasers at λ∼ 8 µm,” J. Nanosci. Nanotechnol. 18(11), 7498–7501 (2018).
[Crossref]

Wang, X. J.

Wang, Z. G.

S. Z. Niu, J. Q. Liu, F. M. Cheng, H. Wang, J. C. Zhang, N. Zhuo, S. Q. Zhai, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, X. H. Wang, and Z. P. Wei, “14 µm quantum cascade lasers based on diagonal transition and nonresonant extraction,” Photonics Res. 7(11), 1244–1248 (2019).
[Crossref]

S. Z. Niu, J. Q. Liu, Y. Zhao, F. M. Cheng, J. C. Zhang, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, Z. P. Wei, and X. H. Wang, “High-Performance Bound-to-Continuum Quantum Cascade Lasers at λ∼ 8 µm,” J. Nanosci. Nanotechnol. 18(11), 7498–7501 (2018).
[Crossref]

Wei, Z. P.

S. Z. Niu, J. Q. Liu, F. M. Cheng, H. Wang, J. C. Zhang, N. Zhuo, S. Q. Zhai, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, X. H. Wang, and Z. P. Wei, “14 µm quantum cascade lasers based on diagonal transition and nonresonant extraction,” Photonics Res. 7(11), 1244–1248 (2019).
[Crossref]

S. Z. Niu, J. Q. Liu, Y. Zhao, F. M. Cheng, J. C. Zhang, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, Z. P. Wei, and X. H. Wang, “High-Performance Bound-to-Continuum Quantum Cascade Lasers at λ∼ 8 µm,” J. Nanosci. Nanotechnol. 18(11), 7498–7501 (2018).
[Crossref]

Wu, D.

Wu, D. H.

Xie F, F.

F. Xie F, C. Caneau, H. P. Leblanc, D. P. Caffey, L. C. Hughes, T. Day, and C.-e. Zah, “Watt-level room temperature continuous-wave operation of quantum cascade lasers with λ> 10 µm[J],” IEEE J. Sel. Top. Quantum Electron. 19(4), 1200407 (2013).
[Crossref]

Yang, Q. K.

Q. K. Yang, C. Schilling, R. Ostendorf, S. Hugger, F. Fuchs, and J. Wagner, “Wall-plug efficiency of mid-infrared quantum cascade lasers,” J. Appl. Phys. 111(5), 053111 (2012).
[Crossref]

Yu, B. L.

J. Sun, H. Deng, N. W. Liu, H. L. Wang, B. L. Yu, and J. S. Li, “Mid-infrared gas absorption sensor based on a broadband external cavity quantum cascade laser,” Rev. Sci. Instrum. 87(12), 123101 (2016).
[Crossref]

Zah, C.-e.

F. Xie F, C. Caneau, H. P. Leblanc, D. P. Caffey, L. C. Hughes, T. Day, and C.-e. Zah, “Watt-level room temperature continuous-wave operation of quantum cascade lasers with λ> 10 µm[J],” IEEE J. Sel. Top. Quantum Electron. 19(4), 1200407 (2013).
[Crossref]

Zhai, S. Q.

S. Z. Niu, J. Q. Liu, F. M. Cheng, H. Wang, J. C. Zhang, N. Zhuo, S. Q. Zhai, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, X. H. Wang, and Z. P. Wei, “14 µm quantum cascade lasers based on diagonal transition and nonresonant extraction,” Photonics Res. 7(11), 1244–1248 (2019).
[Crossref]

Zhang, J. C.

S. Z. Niu, J. Q. Liu, F. M. Cheng, H. Wang, J. C. Zhang, N. Zhuo, S. Q. Zhai, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, X. H. Wang, and Z. P. Wei, “14 µm quantum cascade lasers based on diagonal transition and nonresonant extraction,” Photonics Res. 7(11), 1244–1248 (2019).
[Crossref]

S. Z. Niu, J. Q. Liu, Y. Zhao, F. M. Cheng, J. C. Zhang, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, Z. P. Wei, and X. H. Wang, “High-Performance Bound-to-Continuum Quantum Cascade Lasers at λ∼ 8 µm,” J. Nanosci. Nanotechnol. 18(11), 7498–7501 (2018).
[Crossref]

Zhao, Y.

S. Z. Niu, J. Q. Liu, Y. Zhao, F. M. Cheng, J. C. Zhang, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, Z. P. Wei, and X. H. Wang, “High-Performance Bound-to-Continuum Quantum Cascade Lasers at λ∼ 8 µm,” J. Nanosci. Nanotechnol. 18(11), 7498–7501 (2018).
[Crossref]

Zhou, W.

Zhuo, N.

S. Z. Niu, J. Q. Liu, F. M. Cheng, H. Wang, J. C. Zhang, N. Zhuo, S. Q. Zhai, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, X. H. Wang, and Z. P. Wei, “14 µm quantum cascade lasers based on diagonal transition and nonresonant extraction,” Photonics Res. 7(11), 1244–1248 (2019).
[Crossref]

Appl. Opt. (1)

Appl. Phys. Lett. (2)

N. Bandyopadhyay, Y. Bai Y, S. Slivken, and M. Razeghi, “High power operation of λ∼ 5.2–11 µm strain balanced quantum cascade lasers based on the same material composition,” Appl. Phys. Lett. 105(7), 071106 (2014).
[Crossref]

R Maulini, A Lyakh, A Tsekoun, R. Go, C. Pflüg, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett. 95(15), 151112 (2009).
[Crossref]

IEEE J. Sel. Top. Quantum Electron. (2)

F. Xie F, C. Caneau, H. P. Leblanc, D. P. Caffey, L. C. Hughes, T. Day, and C.-e. Zah, “Watt-level room temperature continuous-wave operation of quantum cascade lasers with λ> 10 µm[J],” IEEE J. Sel. Top. Quantum Electron. 19(4), 1200407 (2013).
[Crossref]

M. Razeghi, “High-performance InP-based mid-IR quantum cascade lasers,” IEEE J. Sel. Top. Quantum Electron. 15(3), 941–951 (2009).
[Crossref]

J. Appl. Phys. (1)

Q. K. Yang, C. Schilling, R. Ostendorf, S. Hugger, F. Fuchs, and J. Wagner, “Wall-plug efficiency of mid-infrared quantum cascade lasers,” J. Appl. Phys. 111(5), 053111 (2012).
[Crossref]

J. Nanosci. Nanotechnol. (1)

S. Z. Niu, J. Q. Liu, Y. Zhao, F. M. Cheng, J. C. Zhang, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, Z. P. Wei, and X. H. Wang, “High-Performance Bound-to-Continuum Quantum Cascade Lasers at λ∼ 8 µm,” J. Nanosci. Nanotechnol. 18(11), 7498–7501 (2018).
[Crossref]

J. Phys. D: Appl. Phys. (1)

D. Botez, C.-C. Chang, and L. J. Mawst, “Temperature sensitivity of the electro-optical characteristics for midinfrared (λ = 3–16 µm)-emitting quantum cascade lasers,” J. Phys. D: Appl. Phys. 49(4), 043001 (2016).
[Crossref]

Meas. Sci. Technol. (1)

J. Hodgkinson and P. Tatam R, “Optical gas sensing: a review,” Meas. Sci. Technol. 24(1), 012004 (2013).
[Crossref]

Opt. Eng. (2)

M. Troccoli, X. Wang, and J. Fan, “Quantum cascade lasers: high-power emission and single-mode operation in the long-wave infrared (> 6 µm),” Opt. Eng. 49(11), 111106 (2010).
[Crossref]

R. P. Leavitt, J. L. Bradshaw, K. M. Lascola, M. Gregory P, M. Frankie, T. Frederick J, and P. John T, “High-performance quantum cascade lasers in the 7.3-to 7.8-µm wavelength band using strained active regions,” Opt. Eng. 49(11), 111109 (2010).
[Crossref]

Opt. Express (6)

Opt. Mater. Express (2)

Photonics Res. (1)

S. Z. Niu, J. Q. Liu, F. M. Cheng, H. Wang, J. C. Zhang, N. Zhuo, S. Q. Zhai, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang, X. H. Wang, and Z. P. Wei, “14 µm quantum cascade lasers based on diagonal transition and nonresonant extraction,” Photonics Res. 7(11), 1244–1248 (2019).
[Crossref]

Rev. Sci. Instrum. (2)

I. Mappé, L. Joly, G. Durry, X. Thomas, T. Decarpenterie, J. Cousin, N. Dumelie, E. Roth, A. Chakir, and P. G. Grillon, “A quantum cascade laser absorption spectrometer devoted to the in situ measurement of atmospheric N2O and CH4 emission fluxes,” Rev. Sci. Instrum. 84(2), 023103 (2013).
[Crossref]

J. Sun, H. Deng, N. W. Liu, H. L. Wang, B. L. Yu, and J. S. Li, “Mid-infrared gas absorption sensor based on a broadband external cavity quantum cascade laser,” Rev. Sci. Instrum. 87(12), 123101 (2016).
[Crossref]

Other (1)

J Faist, Quantum cascade lasers (OUP Oxford, 2013).

Cited By

Optica participates in Crossref's Cited-By Linking service. Citing articles from Optica Publishing Group journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (6)

Fig. 1.
Fig. 1. Band structure and wave functions of relevant energy levels of a bound to continuum and low voltage defect low strain-balanced In0.47Al0.53As/In0.58Ga0.42As LWIR QCL active region design for emitting at λ ∼7.7µm under an applied electric field of 53 kV/cm. The upper (level 4) and lower laser levels (level 5) are shown in red and blue, respectively. The ground state of the injector (level g) is shown in cyan. The red arrow marks the radiative transition.
Fig. 2.
Fig. 2. The calculated waveguide loss αw and confinement factor Γ of the 7.7µm QCL as a function of the numbers of QCL-stages from 30 to 70.
Fig. 3.
Fig. 3. (a) The detailed structure of the device and temperature distribution of a buried ridge QCL epi-down bonded on a diamond heatsink for CW operation. (b) The maximum (Tmax) and average (Tave) core temperature of the buried ridge QCL under CW operation as a function of Ns (Theatsink=300K).
Fig. 4.
Fig. 4. (a) The P-I-V and WPE experimental results at different temperature and (b). characteristic temperatures fitting of a cavity length 4mm, 8µm ridge wide, HR-coated, epi-down device in pulsed operation with duty cycle of 2%. Inset in (a): pulsed emitting spectrum. (c). The P-I-V and WPE experimental results at different temperature in CW operation. Inset in (c): CW laser spectrum at a current of 0.6 A at 293K under water and TEC cooling. (d) The P-I results of uncoated device at different cavity length in pulsed mode. Inset in (d): Inverse external quantum efficiency as a function of cavity length L.
Fig. 5.
Fig. 5. Tuning behavior and peak power of the EC-QCL of the device. Measurements were taken at room temperature with a duty cycle of 2% (10kHz,2 us) at 0.6A.
Fig. 6.
Fig. 6. The beam picture of the QCL measured in pulsed mode at room temperature under a current of 0.5 A with a duty cycle of 8%(40KHz 2us), The horizontal and vertical beam sizes are 2.71mm and 2.26mm, respectively.

Metrics