Extending the effective imaging range of Fourier-domain optical coherence tomography using a fiber optic switch.

The effective imaging range of Fourier-domain optical coherence tomography is limited by falloff. We present a very simple method to extend the effective imaging range with dual reference arms and a high-speed fiber optic switch. The effective imaging range was increased by 1.8 with two reference arms compared with a single reference arm. Ex vivo tissue images show significantly improved sensitivity over a large imaging range. Further extension of the imaging range is feasible with multiple reference arms. The tradeoff between image acquisition rate and imaging range is discussed.