Novel technique of phase stabilisation in swept-source OCT

This work presents a technique designed to correct laser-induced phase variations in Swept-Source optical coherence tomography (SS-OCT) instruments. Conventionally, data resampling is achieved by using an external k-clock module, and the signal generated by taping some of the light and diverting it through a fibre Bragg grating is used to trigger the acquisition and stabilise the phase. Instead, in this work, the nonlinearities in the imaging interferometer output are computed from data generated by a reference interferometer block in synchronism with data collected by the imaging interferometer. Phase-stabilised digital channelled spectra are obtained by monitoring the number of cycles in the output signal of the reference interferometer. Our preliminary results show a significant improvement in the stabilisation of the phase, from an initial 3.6 radians to less than 0.1 radians when using our approach.