Flexible A-scan rate MHz OCT: Computational downscaling by coherent averaging

TL;DR

This paper presents a method to computationally downscale the line rate of MHz OCT systems through coherent averaging, enabling high-quality imaging at lower effective speeds without specialized hardware.

Contribution

It introduces a software-based approach for reducing OCT line rates via coherent averaging, eliminating the need for hardware modifications.

Findings

Coherent averaging effectively reduces system speed from 3.2 MHz to 100 kHz.

High-quality in vivo OCT images of human finger knuckle joint achieved.

No special interferometer designs or digital phase stabilization required.

Abstract

In order to realize fast OCT-systems with adjustable line rate, we investigate averaging of image data from an FDML based MHz-OCT-system. The line rate can be reduced in software and traded in for increased system sensitivity and image quality. We compare coherent and incoherent averaging to effectively scale down the system speed of a 3.2 MHz FDML OCT system to around 100 kHz in postprocessing. We demonstrate that coherent averaging is possible with MHz systems without special interferometer designs or digital phase stabilisation. We show OCT images of a human finger knuckle joint in vivo with very high quality and deep penetration.