Optimization of data processing with the Akinetic swept-laser: algorithm to automatically adjust the A-scan synchronization delay

摘要

The Akinetic swept-laser (Insight, Lafayette, USA) is an all-semiconductor compact and tunable laser source for optical coherence tomography (OCT). Wavelength sweeps with this source are composed of valid data sections interleaved with invalid data sections. The source provides a precise trigger for each wavelength sweep and a "data valid vector" (DVV) file which identifies the indices of the valid data points in a recorded interferogram. In order to identify valid data in real time during acquisition, a delay must be precisely adjusted between the trigger and the wavelength sweep. Optimizing this delay becomes tedious when changing the interferometer configuration in a multi-purpose OCT system. The source provides tools to do this, but they are not automated and require a sample with a single clean reflection. We developed a simple and robust algorithm, integrated in our OCT data acquisition and treatment software, for finding the optimal delay correction that must be applied to accurately identify the valid data obtained with the Akinetic swept-laser. It can perform optimization either from the laser spectrum or from an interferogram and facilitates delay readjustment when the interferometer configuration is modified.