Broadband Impulsive Stimulated Raman Scattering based on a Chirped Detection

TL;DR

This paper introduces CISRS, a novel broadband Raman spectroscopy method using chirped probe pulses that eliminates the need for delay scanning, enabling faster and more efficient measurements of Raman spectra.

Contribution

The paper presents a new CISRS technique that leverages chirped pulses to record Raman spectra without delay scanning, improving speed and efficiency.

Findings

CISRS successfully records broadband Raman spectra without delay scanning.

Experimental demonstrations validate the effectiveness of the chirped probe approach.

The method enhances measurement speed and reduces acquisition time.

Abstract

In Impulsive Stimulated Raman Scattering vibrational oscillations, coherently stimulated by a femtosecond Raman pulse, are real time monitored and read out as intensity modulations in the transmission of a temporally delayed probe pulse. Critically, in order to retrieve broadband Raman spectra, a fine sampling of the time delays between the Raman and probe pulses is required, making conventional ISRS ineffective for probing irreversible phenomena and/or weak scatterers typically demanding long acquisition times, with signal to noise ratios that crucially depend on the pulse fluences and overlap stabilities. To overcome such limitations, here we introduce Chirped based Impulsive Stimulated Raman Scattering (CISRS) technique. Specifically, we show how introducing a chirp in the probe pulse can be exploited for recording the Raman information without scanning the Raman-probe pulse delay. Then we experimentally demonstrate with a few examples how to use the introduced scheme to measure Raman spectra.