Multi-color stimulated Raman scattering with a frame-to-frame wavelength-tunable fiber-based light source

TL;DR

This paper introduces a fast, tunable fiber-based light source for multi-color stimulated Raman scattering imaging, enabling rapid, high-specificity chemical imaging suitable for medical diagnostics outside specialized labs.

Contribution

It presents a novel ultrafast fiber-based light source with frame-to-frame wavelength tuning and low noise, optimized for multi-color SRS imaging.

Findings

Achieves wavelength tuning in under 5 ms across 700-3200 cm$^{-1}$

Outperforms existing fiber-based sources in noise performance for SRS

Enables rapid, high-specificity chemical imaging for medical applications

Abstract

We present multi-color imaging by stimulated Raman scattering (SRS) enabled by an ultrafast fiber-based light source with integrated amplitude modulation and frame-to-frame wavelength tuning. With a relative intensity noise level of -153.7 dBc/Hz at 20.25 MHz the light source is well suited for SRS imaging and outperforms other fiber-based light source concepts for SRS imaging. The light source is tunable in under 5 ms per arbitrary wavelength step between 700 cm$^{-1}$ and 3200 cm$^{-1}$, which allows for addressing Raman resonances from the fingerprint to the CH-stretch region. Moreover, the compact and environmentally stable system is predestined for fast multi-color assessments of medical or rapidly evolving samples with high chemical specificity, paving the way for diagnostics and sensing outside of specialized laser laboratories.