Novel Laser Technology Enables 10x Faster SRS Imaging and Rapid Tuning in Biological Samples

Abstract

Stimulated Raman Scattering (SRS) microscopy was developed for the label-free detection of molecular groups, addressing the speed limitations of spontaneous Raman microscopy. Standard SRS microscopy typically operates with laser sources at an 80 MHz repetition rate and a color-tuning speed of approximately 0.1 Hz to target different molecular groups. Here, we present a novel laser system that overcomes these speed limitations, achieving an order-of-magnitude improvement in both color-tuning and imaging speed. Our system features a reduced repetition rate of 40 MHz, enabling SRS imaging that is ten times faster than standard systems while maintaining the same average power at the sample. This is achieved through increased pulse energy and laser modulation at half the repetition rate. Furthermore, the system provides nearly ten times faster color-tuning across an extended range (660-1010 nm) by employing angle-tuning of nonlinear crystals instead of temperature-tuning. The improved performance is demonstrated in direct comparison with a standard SRS laser system, showcasing the potential for significantly enhanced imaging capabilities.