We present a technique for improved carrier generation by eliminating the instability of a mechanical device in favor of an electro-optical phase modulator in the reference arm of an optical coherence tomography system. A greater than threefold reduction in the phase variance between consecutive A-line scans at a repetition rate of 1 kHz was achieved. Stable and reproducible interference fringe generation permits phase-resolved digital data processing. A correction algorithm was applied to the interferometric signal to compensate for the departure of the source spectrum from an ideal Gaussian shape, resulting in up to 8-dB sidelobe suppression at the expense of a 1-dB increase in the noise floor. In addition, we could eliminate completely the broadening effect of group-delay dispersion on the coherence function by introducing a quadratic phase shift in the Fourier domain of the interferometric signal.
© 2001 Optical Society of America
(120.5050) Instrumentation, measurement, and metrology : Phase measurement
(120.5060) Instrumentation, measurement, and metrology : Phase modulation
(170.0170) Medical optics and biotechnology : Medical optics and biotechnology
(170.3010) Medical optics and biotechnology : Image reconstruction techniques
(170.4500) Medical optics and biotechnology : Optical coherence tomography
Johannes F. de Boer, Christopher E. Saxer, and J. Stuart Nelson, "Stable Carrier Generation and Phase-Resolved Digital Data Processing in Optical Coherence Tomography," Appl. Opt. 40, 5787-5790 (2001)