Fiber-based optical delay line for OCT system

We have implemented an all-fiber optical delay line, which is composed of fiber optic components such as two linearly chirped fiber Bragg gratings, fiber optic coupler and circulator. The proposed all-fiber delay line possesses features of automatic dispersion compensation and amplified optical delay. Using the fundamental characteristics of chirped fiber Bragg gratings, the basic properties are derived to appreciate the principle of all-fiber delay line. We obtained the experimental results that reveals group delay cancellation and amplified optical delay. The non-invasive cross-sectional images of biological and transparent glass samples are acquired with the proposed all-fiber delay line, which validates the potential as an optical delay line and its feasibility for optical coherence tomography.