Amplified Dispersive Optical Tomography

TL;DR

This paper introduces a novel optical coherence tomography technique using Raman amplification and dispersive Fourier transformation to enhance sensitivity and depth range without reducing speed, demonstrated at 36.6 MHz.

Contribution

It presents a new method combining Raman amplification with dispersive Fourier transformation to improve OCT performance beyond traditional limits.

Findings

15 dB sensitivity improvement in single-shot imaging

Achieved axial scan rate of 36.6 MHz

Extended depth range without increasing damage risk

Abstract

Optical coherence tomography (OCT) has proven to be a powerful technique for studying tissue morphology in ophthalmology, cardiology, and endomicroscopy. Its performance is limited by the fundamental trade-off between the imaging sensitivity and acquisition speed -- a predicament common in virtually all imaging systems. In this paper, we circumvent this limit by using distributed Raman post-amplification of the reflection from the sample. We combine the amplification with simultaneously performed dispersive Fourier transformation, a process that maps the optical spectrum into an easily measured time-domain waveform. The Raman amplification enables measurement of weak signals which are otherwise buried in noise. It extends the depth range without sacrificing the acquisition speed or causing damage to the sample. As proof of concept, single-shot imaging with 15 dB improvement in sensitivity at an axial scan rate of 36.6 MHz is demonstrated.