Abstract

We report a new rapid-scanning optical delay device suitable for high-speed optical coherence tomography (OCT) in which an acousto-optic modulator (AOM) is used to independently modulate the Doppler frequency shift of the reference light beam for optical heterodyne detection. Experimental results show that the fluctuation of the measured Doppler frequency shift is less than ±0.2% over 95% duty cycle of OCT imaging, thus allowing for enhanced signal-to-noise ratio of optical heterodyne detection. The increased Doppler frequency shift by AOM also permits complete envelop demodulation without the compromise of reducing axial resolution; if used with a resonant rapid-scanning optical delay, it will permit high-performance real-time OCT imaging. Potentially, this new rapid-scanning optical delay device will improve the performance of high-speed Doppler OCT techniques.

© 2003 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |

  1. D. Huang, E. A. Swanson, C. P. Lin, J. S. Schuman, W. G. Stinson, W. Chang, M. R. Hee, T. Flotte, K. Gregory, C. A. Puliafito, and J. G. Fujimoto, �??Optical Coherence Tomography,�?? Science 254, 1178-1181 (1991)
    [CrossRef] [PubMed]
  2. Johannes F. de Boer, Shyam M. Srinivas, Arash Malekafzali, Zhongping Chen, and J. Stuart Nelson, �??Imaging thermally damaged tissue by polarization sensitive optical coherence tomography,�?? Opt. Express 3, 212-218 (1998), <a href="http://www.opticsexpress.org/abstract.cfm?URI=OPEX-3-6-212">http://www.opticsexpress.org/abstract.cfm?URI=OPEX-3-6-212</a>.
    [CrossRef] [PubMed]
  3. Gang Yao, Lihong Wang, �??Propagation of polarized light in turbid media: simulated animation sequences,�?? Opt. Express 7, 198-203 (2000), <a href="http://www.opticsexpress.org/abstract.cfm?URI=OPEX-7-5-198">http://www.opticsexpress.org/abstract.cfm?URI=OPEX-7-5-198</a>.
    [CrossRef] [PubMed]
  4. Volker Westphal, Siavash Yazdanfar, Andrew M. Rollins, Joseph A. Izatt, �??Real-time, high velocity resolution color Doppler optical coherence tomography,�?? Opt. Lett. 27, 34-36 (2002).
    [CrossRef]
  5. M. Wojtkowski, A. Kowalczyk, R. Leitgeb, A. F. Fercher, �??Full range complex spectral optical coherence tomography technique in eye imaging,�?? Opt. Lett. 27, 1415-1417 (2002).
    [CrossRef]
  6. W. Drexler, U. Morgner, F. X. Kartner, C. Pitris, S. A. Boppart, X. D. Li, E. P. Ippen, and J. G. Fujimoto, �??In vivo ultrahigh-resolution optical coherence tomography,�?? Opt. Lett. 24, 1221-1223 (1999).
    [CrossRef]
  7. J. M. Schmitt, �??Optical Coherence Tomography (OCT): A Review,�?? IEEE J. of Selected Topics in Quantum Electron. 5, 1205-1215 (1999).
    [CrossRef]
  8. K. F. Kwong, D. Yankelevich, K. C. Chu, J. P. Heritage, and A. Dienes, �??400-Hz mechanical scanning optical delay line,�?? Opt. Lett. 18, 558-560 (1993).
    [CrossRef] [PubMed]
  9. G. J. Tearney, B. E. Bouma, and J. G. Fujimoto, �??High-speed phase- and group-delay scanning with a grating-based phase control delay line,�?? Opt. Lett. 22, 1811-1813 (1997).
    [CrossRef]
  10. N. Chen and Q. Zhu, �??Rotary mirror array for high-speed optical coherence tomography,�?? Opt. Lett. 27, 607-609 (2002).
    [CrossRef]
  11. P. Hsiung, X. Li, C. Chudoba, I. Hartl, T. H. Ko, and J. G. Fujimoto, �??High-speed path-length scanning with a multiple-pass cavity delay line,�?? Appl. Opt. 42, 640-648 (2003).
    [CrossRef] [PubMed]
  12. Y. Zhao, Z. Chen, C. Saxer, S. Xiang, J. F. de Boer, and J. S. Nelson, �??Phase-resolved optical coherence tomography and optical Doppler tomography for imaging blood flow in human skin with fast scanning speed and high velocity sensitivity,�?? Opt. Lett. 25, 114-116 (2000).
    [CrossRef]
  13. New Focus, �??Practical Uses and Applications of Electro-Optic Modulators,�?? Application Notes 2, <a href="http://www.newfocus.com">http://www.newfocus.com></a>.
  14. M. R. Fetterman, J. C. Davis, H. -S. Tan, W. Yang, D. Goswami, J. �??K. Rhee, and W. S. Warren, �??Fast-frequency-hopping modulation and detection demonstration,�?? J. Opt. Soc. Am. B 18, 1372-1376 (2001).
    [CrossRef]
  15. M. Rollins, M. D. Kulkarni, S. Yazdanfar, R. Ung-arunyawee, and J. A. Izatt, �??In vivo video rate optical coherence tomography,�?? Opt. Express 3, 219-229 (1998), <a href="http://www.opticsexpress.org/abstract.cfm?URI=OPEX-3-6-219">http://www.opticsexpress.org /abstract.cfm?URI=OPEX-3-6-219</a>.
    [CrossRef] [PubMed]
  16. Y. T. Pan, R. Birngruber, R. Rosperich, and R. Engelhardt, �??Optical coherence tomography in turbid tissues: theoretical analysis,�?? Appl. Opt. 34, 6564-6574 (1995).
    [CrossRef] [PubMed]
  17. V. Westphal, S. Yazdanfar, A. Rollins, and J. Izatt, �??Real-time, high velocity-resolution color Doppler optical coherence tomography,�?? Opt. Lett. 27, 34-36 (2002).
    [CrossRef]
  18. T. Q. Xie, M. L. Zeidel, and Y. T. Pan,"Detection of tumorigenesis in urinary bladder with optical coherence tomography: optical characterization of morphological changes," Opt. Express 10, 1431- 1443 (2002), <a href="http://www.opticsexpress.org/abstract.cfm?URI=OPEX-10-24-1431">http://www.opticsexpress.org/abstract.cfm?URI=OPEX-10-24-1431</a>.
    [CrossRef] [PubMed]
  19. Yingtian Pan, Tuqiang Xie, Sheldon Bastacky, Susan Meyers, and Mark Zeidel, �??Enhancing early bladder cancer detection with fluorescence-guided endoscopic optical coherence tomography,�?? Opt. Lett. in print (2003).
    [CrossRef] [PubMed]

Appl. Opt. (2)

Application Notes 2 (1)

New Focus, �??Practical Uses and Applications of Electro-Optic Modulators,�?? Application Notes 2, <a href="http://www.newfocus.com">http://www.newfocus.com></a>.

IEEE J. of Sel. Topics in Quant. Electr. (1)

J. M. Schmitt, �??Optical Coherence Tomography (OCT): A Review,�?? IEEE J. of Selected Topics in Quantum Electron. 5, 1205-1215 (1999).
[CrossRef]

J. Opt. Soc. Am. B (1)

Opt. Express (4)

Opt. Lett. (9)

Volker Westphal, Siavash Yazdanfar, Andrew M. Rollins, Joseph A. Izatt, �??Real-time, high velocity resolution color Doppler optical coherence tomography,�?? Opt. Lett. 27, 34-36 (2002).
[CrossRef]

M. Wojtkowski, A. Kowalczyk, R. Leitgeb, A. F. Fercher, �??Full range complex spectral optical coherence tomography technique in eye imaging,�?? Opt. Lett. 27, 1415-1417 (2002).
[CrossRef]

W. Drexler, U. Morgner, F. X. Kartner, C. Pitris, S. A. Boppart, X. D. Li, E. P. Ippen, and J. G. Fujimoto, �??In vivo ultrahigh-resolution optical coherence tomography,�?? Opt. Lett. 24, 1221-1223 (1999).
[CrossRef]

K. F. Kwong, D. Yankelevich, K. C. Chu, J. P. Heritage, and A. Dienes, �??400-Hz mechanical scanning optical delay line,�?? Opt. Lett. 18, 558-560 (1993).
[CrossRef] [PubMed]

G. J. Tearney, B. E. Bouma, and J. G. Fujimoto, �??High-speed phase- and group-delay scanning with a grating-based phase control delay line,�?? Opt. Lett. 22, 1811-1813 (1997).
[CrossRef]

N. Chen and Q. Zhu, �??Rotary mirror array for high-speed optical coherence tomography,�?? Opt. Lett. 27, 607-609 (2002).
[CrossRef]

Yingtian Pan, Tuqiang Xie, Sheldon Bastacky, Susan Meyers, and Mark Zeidel, �??Enhancing early bladder cancer detection with fluorescence-guided endoscopic optical coherence tomography,�?? Opt. Lett. in print (2003).
[CrossRef] [PubMed]

V. Westphal, S. Yazdanfar, A. Rollins, and J. Izatt, �??Real-time, high velocity-resolution color Doppler optical coherence tomography,�?? Opt. Lett. 27, 34-36 (2002).
[CrossRef]

Y. Zhao, Z. Chen, C. Saxer, S. Xiang, J. F. de Boer, and J. S. Nelson, �??Phase-resolved optical coherence tomography and optical Doppler tomography for imaging blood flow in human skin with fast scanning speed and high velocity sensitivity,�?? Opt. Lett. 25, 114-116 (2000).
[CrossRef]

Science (1)

D. Huang, E. A. Swanson, C. P. Lin, J. S. Schuman, W. G. Stinson, W. Chang, M. R. Hee, T. Flotte, K. Gregory, C. A. Puliafito, and J. G. Fujimoto, �??Optical Coherence Tomography,�?? Science 254, 1178-1181 (1991)
[CrossRef] [PubMed]

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 (6)

Fig. 1.
Fig. 1.

A sketch of an optical coherence tomographic imaging system using acousto-optic modulation. A fiberoptic acousto-optic modulator (AOM) is inserted in the reference arm to provide a stable 2MHz (tunable) frequency modulation. In combination with a RSOD, this allows for high-performance reference scanning for high-speed OCT imaging, BBS: broadband source: BBS; LD: aiming laser diode; PD: photo diode; CM: fiber-optic collimator.

Fig. 2.
Fig. 2.

Recorded modulated and linearly demodulated interferometric signals without using acousto-optic modulation. The servo mirror was driven with a 500 Hz triangular waveform, and the pivot offset x=2mm. ΔT relates to the measured coherence length Lc. Artifacts such as serve ripples resulted from incomplete demodulation is obvious.

Fig. 3.
Fig. 3.

Measured Doppler frequency changes with depth in OCT scanning system without using AOM. (a) Servo mirror was driven by a 500 Hz triangular waveform. Frequency variation δf is less than 25% for 80% duty cycle and increases 63% for 90% duty cycle. (b) Servo mirror was driven by a 500 Hz sinusoidal waveform. δf is 56% for 90% duty cycle.

Fig. 4.
Fig. 4.

Recorded modulated OCT transient signal (a) and demodulated interferometric signal (b) using AOM-mediated RSOD. The pivot offset x=0mm, and the AOM was modulated at fD/AOM=2MHz. The measured carrier frequency 1/ΔT=2MHz. Linear amplitude demodulation is clean and complete. ΔT related to the measured coherence length Lc.

Fig. 5.
Fig. 5.

Measured Doppler frequency changes with depth in scanning system using AOM mediated RSOD. (a) Servo mirror was driven by a 500 Hz triangular waveform. (b) Servo mirror was driven by sinusoidal waveform. The measured frequency instability is less than 0.39% over 95% duty cycle. The large error bar was primarily caused by measurement errors.

Fig. 6.
Fig. 6.

Porcine bladder imaged by OCT with AOM-mediated RSOD. U: normal urothelium, SM: submucosa, M: muscular layer. The 2D-OCT image size is 2×5 mm2 displayed in grayscale (linear demodulation). Signal level ranged from -40dB (bright) to -100dB (dark).

Equations (5)

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

I ( Δ L r g , Δ L r p ) 2 I s I r . η R ( Δ L r g ) C A ( Δ L r g ) . cos k ¯ Δ L r p
f D = 4 x ω λ 0
Δ f = 4 x ω Δ λ λ 0 2 4 ω f Δ λ p λ 0 4 ω f Δ λ λ 0 p
f D AOM = 4 x ω λ 0 + f AOM = f AOM
I ( Δ L r g , t ) 2 I s I r · η R ( Δ L r g ) C A ( Δ L r g ) · cos ( f AOM t )

Metrics