Chromatic optical coherence tomography with extended depth of field

Abstract

Optical coherence tomography (OCT) is an optical imaging modality that provides high-sensitive and non-invasive tomographic image with high spatial resolution. And by using high NA objective lens and broadband light source, the resolution of the system can be further improved in the order of 1~3 µm. Despite these high-resolution imaging capabilities, limited axial depth of field caused by high NA objective significantly limits the functionality. In this study, utilizing axial chromatic focal shift was proposed to overcome this limitation. OCT imaging simulation was implemented to evaluate the performance change before and after adapting axial chromatic focal shift. Also, high-resolution OCT system with resolution of 3 µm and depth of field of 340 µm was developed. The simulation and experiment results were largely consistent, and therefore, I successfully analyzed the performance change caused by chromatic focal shift numerically. Through this, I suggest to utilize axial chromatic focal shift in high-resolution OCT system in order to extend the depth of field.