Broadband Wavelength Swept Laser With Bidirectional Photonic Resonance for High Resolution Optical Coherence Tomography

A light source with extended spectral bandwidth applied in optical coherence tomography (OCT) systems produces highly accurate micro-scale imaging structures owing to the attainable high-axial resolution. This study presents a wide tuning range of a wavelength-swept laser to improve the axial resolution. Linear cavity configuration was performed for bidirectional photonic resonance using two semiconductor optical amplifiers placed parallelly. A polygon scanner-based tunable filter produced a broad scanning range of 155 nm from 917 nm to 1072 nm and an axial resolution of 3.4 μm in air. Bench-top imaging of a phantom made of food wraps was performed with 22.6 μm transverse resolution to evaluate the performance of the swept laser for high-resolution OCT.