Calibration method for high-resolution single mode fiber optic spectrometers for optical coherence tomography

Abstract

In our method, we calibrate the high-resolution frequency domain optical coherence tomography (FD-OCT) spectrometer using a single mode fiber optic Michelson interferometer coupled with a broadband super-luminescent light emitting diode (SLED) source, used in the very same FD-OCT system. The SLED light is filtered by the Michelson interferometer and exhibits equally spaced in the frequency domain fringes. The spacing of these fringes is controlled by the difference in arm's length of the spectrometer. By performing measurements for several values of differences in optical paths between arms in Michelson interferometers we find the nonlinear dispersion of the grating spectrometer. We use this dispersion when employing the FD-OCT system as a distance gauge.