2019/10/28 by Xavier Audier, Sandro Heuke, Audier, Xavier +7 · 2 citations
Biochemistry, Genetics and Molecular Biology · Chemistry · Engineering · Medicine · Physics and Astronomy · #Applied Physics (physics.app-ph) #Artificial intelligence #Avalanche photodiode #Computer science #Context (archaeology) #Detector #Electronic engineering #Engineering #FOS: Physical sciences #Instrumentation and Detectors (physics.ins-det) #Laser #Laser power scaling #Noise (video) #Optical Imaging and Spectroscopy Techniques #Optics #Optics (physics.optics) #Optoelectronics #Photoacoustic and Ultrasonic Imaging #Photodiode #Physics #Raman scattering #Raman spectroscopy #Relative intensity noise #Semiconductor laser theory #Sensitivity (control systems) #Spectroscopy Techniques in Biomedical and Chemical Research #Spectroscopy and Chemometric Analyses #physics.app-ph #physics.ins-det #physics.optics
paper · pdf · open access · doi:10.48550/arxiv.1910.12777
published in Figshare (Figshare (United Kingdom))
arxiv created 2019/10/28 · arxiv updated 2019/10/29 · openalex created_date 2022/11/11 · openalex publication_date 2023/11/30 · openalex updated_date 2026/08/06
We revisit laser intensity noise in the context of stimulated Raman scattering (SRS), which has recently proved to be a key technique to provide label free images of chemical bonds in biological and medical samples. Contrary to most microscopy techniques, which detect a weak photon flux resulting from light matter interactions, SRS is a pump-probe scheme that works in the high flux regime and happens as a weak modulation (10-4-10-6) in a strong laser field. As a result, laser noise is a key issue in SRS detection. This practical tutorial provides the experimentalists with the tools required to assess the amount of noise and the ultimate SRS detection limit in a conventional lock-in-based SRS system. We first define the quantities that are relevant when discussing intensity noise, and illustrate them through a conventional model of light detection by a photodiode. Stimulated Raman Scattering is then introduced in its lock-in-based implementation, and the model presented is adapted in this particular case. The power spectral density (PSD), relative intensity noise (RIN), signal to noise ratio (SNR), and sensitivity of the system are derived and discussed. Two complementary methods are presented that allow measurement of the RIN and assessment of the performance of a SRS system. Such measurements are illustrated on two commercial laser systems. Finally, the consequences of noise in SRS are discussed, and future developments are suggested. The presentation is made simple enough for under-graduated, graduated students, and newcomers in the field of stimulated Raman, and more generally in pump-probe based schemes.