Abstract

The use of diffraction gratings as tuning devices in laser resonators is well known and has been demonstrated abundantly for CO2 lasers. As the grating rotates, the lines of the infrared spectrum of the CO2 molecule reach threshold and oscillate one by one. Here it is shown that it is possible to obtain the same spectrum by moving an aperture inside the cavity perpendicularly to the laser axis while keeping the grating stationary. The conditions for obtaining a well-resolved spectrum are formulated for both the rotating grating and the moving aperture case.

© 2003 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. G. Moeller, J. D. Rigden, “Observation of laser action in the R-branch of CO2 and N2O vibrational spectra,” Appl. Phys. Lett. 8, 69–70 (1966).
    [CrossRef]
  2. T. Hewagama, U. P. Oppenheim, M. J. Mumma, “Anomalous gain in an isotopically mixed CO2 laser and application to absolute wavelength calibration,” IEEE J. Quantum Electron. 27, 465–470 (1991).
    [CrossRef]
  3. A. E. Siegman, Lasers (University Science, Mill Valley, Calif., 1986), p. 751.
  4. N. Djeu, T. Kan, J. Wolga, “Gain distribution, population densities and rotational temperature for the (0001)–(1000) rotation-vibration transitions in a flowing CO2–N2–He laser,” IEEE J. Quantum Electron. QE-4, 256–260 (1968).
    [CrossRef]
  5. A. G. Fox, T. Li, “Resonant modes in a maser interferometer,” Bell Syst. Tech. J. 40, 453–458 (1961).
    [CrossRef]
  6. L. W. Casperson, S. D. Lunnam, “Gaussian modes in high loss laser resonators,” Appl. Opt. 14, 1193–1199 (1975).
    [CrossRef] [PubMed]
  7. R. Hauck, H. P. Kortz, H. Weber, “Misalignment sensitivity of optical resonators,” Appl. Opt. 19, 598–601 (1980).
    [CrossRef] [PubMed]
  8. A. Maitland, M. H. Dunn, Laser Physics (North-Holland, Amsterdam, 1969), pp. 312–315.

1991 (1)

T. Hewagama, U. P. Oppenheim, M. J. Mumma, “Anomalous gain in an isotopically mixed CO2 laser and application to absolute wavelength calibration,” IEEE J. Quantum Electron. 27, 465–470 (1991).
[CrossRef]

1980 (1)

1975 (1)

1968 (1)

N. Djeu, T. Kan, J. Wolga, “Gain distribution, population densities and rotational temperature for the (0001)–(1000) rotation-vibration transitions in a flowing CO2–N2–He laser,” IEEE J. Quantum Electron. QE-4, 256–260 (1968).
[CrossRef]

1966 (1)

G. Moeller, J. D. Rigden, “Observation of laser action in the R-branch of CO2 and N2O vibrational spectra,” Appl. Phys. Lett. 8, 69–70 (1966).
[CrossRef]

1961 (1)

A. G. Fox, T. Li, “Resonant modes in a maser interferometer,” Bell Syst. Tech. J. 40, 453–458 (1961).
[CrossRef]

Casperson, L. W.

Djeu, N.

N. Djeu, T. Kan, J. Wolga, “Gain distribution, population densities and rotational temperature for the (0001)–(1000) rotation-vibration transitions in a flowing CO2–N2–He laser,” IEEE J. Quantum Electron. QE-4, 256–260 (1968).
[CrossRef]

Dunn, M. H.

A. Maitland, M. H. Dunn, Laser Physics (North-Holland, Amsterdam, 1969), pp. 312–315.

Fox, A. G.

A. G. Fox, T. Li, “Resonant modes in a maser interferometer,” Bell Syst. Tech. J. 40, 453–458 (1961).
[CrossRef]

Hauck, R.

Hewagama, T.

T. Hewagama, U. P. Oppenheim, M. J. Mumma, “Anomalous gain in an isotopically mixed CO2 laser and application to absolute wavelength calibration,” IEEE J. Quantum Electron. 27, 465–470 (1991).
[CrossRef]

Kan, T.

N. Djeu, T. Kan, J. Wolga, “Gain distribution, population densities and rotational temperature for the (0001)–(1000) rotation-vibration transitions in a flowing CO2–N2–He laser,” IEEE J. Quantum Electron. QE-4, 256–260 (1968).
[CrossRef]

Kortz, H. P.

Li, T.

A. G. Fox, T. Li, “Resonant modes in a maser interferometer,” Bell Syst. Tech. J. 40, 453–458 (1961).
[CrossRef]

Lunnam, S. D.

Maitland, A.

A. Maitland, M. H. Dunn, Laser Physics (North-Holland, Amsterdam, 1969), pp. 312–315.

Moeller, G.

G. Moeller, J. D. Rigden, “Observation of laser action in the R-branch of CO2 and N2O vibrational spectra,” Appl. Phys. Lett. 8, 69–70 (1966).
[CrossRef]

Mumma, M. J.

T. Hewagama, U. P. Oppenheim, M. J. Mumma, “Anomalous gain in an isotopically mixed CO2 laser and application to absolute wavelength calibration,” IEEE J. Quantum Electron. 27, 465–470 (1991).
[CrossRef]

Oppenheim, U. P.

T. Hewagama, U. P. Oppenheim, M. J. Mumma, “Anomalous gain in an isotopically mixed CO2 laser and application to absolute wavelength calibration,” IEEE J. Quantum Electron. 27, 465–470 (1991).
[CrossRef]

Rigden, J. D.

G. Moeller, J. D. Rigden, “Observation of laser action in the R-branch of CO2 and N2O vibrational spectra,” Appl. Phys. Lett. 8, 69–70 (1966).
[CrossRef]

Siegman, A. E.

A. E. Siegman, Lasers (University Science, Mill Valley, Calif., 1986), p. 751.

Weber, H.

Wolga, J.

N. Djeu, T. Kan, J. Wolga, “Gain distribution, population densities and rotational temperature for the (0001)–(1000) rotation-vibration transitions in a flowing CO2–N2–He laser,” IEEE J. Quantum Electron. QE-4, 256–260 (1968).
[CrossRef]

Appl. Opt. (2)

Appl. Phys. Lett. (1)

G. Moeller, J. D. Rigden, “Observation of laser action in the R-branch of CO2 and N2O vibrational spectra,” Appl. Phys. Lett. 8, 69–70 (1966).
[CrossRef]

Bell Syst. Tech. J. (1)

A. G. Fox, T. Li, “Resonant modes in a maser interferometer,” Bell Syst. Tech. J. 40, 453–458 (1961).
[CrossRef]

IEEE J. Quantum Electron. (2)

T. Hewagama, U. P. Oppenheim, M. J. Mumma, “Anomalous gain in an isotopically mixed CO2 laser and application to absolute wavelength calibration,” IEEE J. Quantum Electron. 27, 465–470 (1991).
[CrossRef]

N. Djeu, T. Kan, J. Wolga, “Gain distribution, population densities and rotational temperature for the (0001)–(1000) rotation-vibration transitions in a flowing CO2–N2–He laser,” IEEE J. Quantum Electron. QE-4, 256–260 (1968).
[CrossRef]

Other (2)

A. E. Siegman, Lasers (University Science, Mill Valley, Calif., 1986), p. 751.

A. Maitland, M. H. Dunn, Laser Physics (North-Holland, Amsterdam, 1969), pp. 312–315.

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (9)

Fig. 1
Fig. 1

Schematic diagram of a CO2 laser (not to scale) with a discharge length of 58 cm and a total resonator length of 390 cm.

Fig. 2
Fig. 2

(a) Observed spectrum of the P-branch of the 10.4-μm band of a CO2 laser as a function of wavelength, obtained by rotation of the grating. Slit width, 4 mm. (b) Same as (a) but with a slit width of 7 mm.

Fig. 3
Fig. 3

Explanation of CO2 spectrum formation with a scanning slit (S) inside the cavity. The discharge region is omitted for clarity, and angular dispersion of the grating is greatly exaggerated.D, displacement of the beam center (dashed line) of λ′ with respect to the beam center of λ; s, slit width; 2w, spot diameter; M, output coupling mirror.

Fig. 4
Fig. 4

Slit scan of the P-branch of the 10.4-μm band of a CO2 laser as a function of wavelength. Slit width, 4 mm.

Fig. 5
Fig. 5

(a) Grating scan of the R branch of the 9.4-μm band of a CO2 laser as a function of wavelength, with R(14) missing. (b) Slit scan of the R branch of the 9.4-μm band of a CO2 laser as a function of wavelength, with R(14) missing.

Fig. 6
Fig. 6

Grating scan of the P branch of the 10.4-μm band of a CO2 laser as a function of wavelength, without a slit in the cavity. The data points are at wavelengths for which the power was measured and do not indicate rotational lines of CO2. The horizontal bar shows the wavelength range of each output power measurement.

Fig. 7
Fig. 7

Calculated beam profile of the P(20) line of the P branch of a CO2 laser as a function of distance from the laser axis for the lowest-order resonant mode. Abscissa, normalized distance in units of distance divided by w. Also shown is the P(22) line, displaced by D from P(20). 2w, laser spot diameter.

Fig. 8
Fig. 8

Observed output power of the P(20) line of the P branch of a CO2 laser as a function of the displacement of the slit from the laser axis. The grating is replaced by a plane mirror in these measurements. Squares, s = 4 mm; circles, s = 5 mm; triangles, s = 6.5 mm. Ordinate, power observed with s = 4 mm. The other curves are normalized to the curve for s = 4 mm.

Fig. 9
Fig. 9

Observed slit scan for the P(20) and P(22) lines of the P branch of a CO2 laser as a function of displacement of the scanning slit from the laser axis, for slit widths of 4.2 and 5.0 mm.

Equations (5)

Equations on this page are rendered with MathJax. Learn more.

2d sin α=mλ,
2w=2λL/π1/21/g1-g1/4,
dα=dλ/2d cos α
I=I0 exp-2r2/w2,
P=P01-exp-2a2/w2.

Metrics