Improving the signal-to-noise ratio of spontaneous Raman systems using ultranarrow linewidth fiber lasers

Abstract Ultranarrow linewidth fiber lasers have good application prospects in high-precision spontaneous Raman detection systems due to their excellent frequency stability and low phase noise characteristics. This study first presents a theoretical derivation of the influence between laser linewidth and Raman detection performance, focusing on signal-to-noise ratio (SNR). Subsequently, a self-developed ultranarrow linewidth fiber laser, featuring a linewidth of 650 Hz, is utilized to experimentally validate the influence of laser linewidth on SNR. The results demonstrate that reducing the laser linewidth from 200 kHz to 650 Hz improves the SNR of mid frequency spectra by a factor of 1.58. This work offers both a theoretical foundation and experimental evidence to support the optimization of Raman system design.