Submicrosecond speed optical coherence tomography system design and analysis by use of acousto-optics

    Authors

    N. A. Riza;Z. Yaqoob

    Abbreviated Journal Title

    Appl. Optics

    Keywords

    Optics

    Abstract

    A novel high-speed no-moving-parts optical coherence tomography (OCT) system is introduced that acquires sample data at less than a microsecond per data point sampling rate. The basic principle of the proposed OCT system relies on use of an acousto-optic deflector. This OCT system has the attractive features of an acousto-optic scanning heterodyne interferometer coupled with an acousto-optic (AO) variable optical delay line operating in a reflective mode. Fundamentally, OCT systems use a broadband light source for high axial resolution inside the sample or living tissue under examination. Inherently, AO devices are Bragg-mode wavelength-sensitive elements. We identify that two beams generated by a Bragg cell naturally have unbalanced and inverse spectrums with respect to each other. This mismatch in spectrums in turn violates the ideal autocorrelation condition for a high signal-to-noise ratio broadband interferometric sensor such as OCT. We solve this fundamental limitation of Bragg cell use for OCT by deploying a new interferometric architecture where the two interfering beams have the same power spectral profile over the bandwidth of the broadband source. With the proposed AO based system, high (e.g., megahertz) intermediate frequency can be generated for low 1/f noise heterodyne detection. System issues such as resolution, number of axial scans, and delay-path selection time are addressed. Experiments described demonstrate our high-speed acousto-optically tuned OCT system where optical delay lines can be selected at submicrosecond speeds. (C) 2003 Optical Society of America.

    Journal Title

    Applied Optics

    Volume

    42

    Issue/Number

    16

    Publication Date

    1-1-2003

    Document Type

    Article; Proceedings Paper

    Language

    English

    First Page

    3018

    Last Page

    3026

    WOS Identifier

    WOS:000183256600020

    ISSN

    1559-128X

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