Fiber-based stray light suppression in spectroscopy using periodic shadowing

Stray light is a known strong interference in spectroscopic measurements. Photons from high-intensity signals that are scattered inside the spectrometer, or photons enter detector through unintended ways, will be added to spectrum as an signal. A general experimental solution this problem presented here by introducing customized fiber for signal collection. The fiber-mount spectrometer consists of periodically arranged array that, combined with lock-in analysis data, capable suppressing stray improved spectroscopy. method, which referred fiber-based periodic shadowing, was applied Raman spectroscopy combustion. stray-light suppression method implemented setup high-power high-repetition-rate laser system used measurements different room-temperature gas mixtures and premixed flame. It shown level reduced up factor 80. Weak spectral lines can distinguished, therefore better molecular species identification, well concentration temperature evaluation, were performed. results show feasible efficient practical use it employed tool improving accuracy.