Ultrahigh-speed optical coherence tomography based on a 100 MHz and 100 nm swept source

TL;DR

This paper presents an ultrahigh-speed optical coherence tomography system using a 100 MHz, 100 nm swept source, achieving high resolution and imaging quality for fast rotating disks.

Contribution

It introduces a novel 100 MHz swept source with broad bandwidth and demonstrates its application in high-speed, high-resolution OCT imaging.

Findings

Achieved 21 μm axial resolution.

Demonstrated imaging of a rotating disk at 17,000 rpm.

Maintained high sensitivity over 3 mm depth.

Abstract

We demonstrate an ultrahigh-speed optical coherence tomography (OCT) based on a 100 MHz swept source (SS). An all polarization-maintaining figure-9 mode-locked fiber laser is used as the seed laser. After nonlinear spectral expansion in an Erbium-doped fiber amplifier, a flat top spectrum with respectively 1-dB and 10-dB bandwidths of 73.7 nm and 106 nm is obtained. The broadband femtosecond pulse is time stretched to a swept signal in a section of dispersion compensation fiber with a total dispersion of -84 ps/nm. With the swept source, the axial resolution of the SS-OCT is measured to be 21 um with a 6 dB sensitivity roll-off length of 3 mm. A tomographic image of an encoding disk and a hard disk jointly rotating at 17,000 rpm was acquired by using the SS-OCT with a high imaging quality.