Constructing a Micro-Raman Spectrometer with Industrial-Grade CMOS Camera—High Resolution and Sensitivity at Low Cost

Until now, achieving both a high spectral resolution on the order of a few wavenumbers and the highest sensitivity in Raman scattering spectroscopy has required reliance on high-end laboratory instruments. Here, we introduce an innovative yet design-wise simple alternative: a cost-effective and compact micro-Raman spectrometer (µRS) that combines exceptional spectral resolution and sensitivity. Leveraging industrial-grade CMOS cameras and high-quality photographic objectives, our µRS maintains a footprint at least five times smaller than traditional lab-based spectrometers. Through detailed characterization and direct experimental comparison, which includes the use of calcite as a Raman standard, we demonstrate that our µRS achieves a spectral resolution of down to 2.5 cm−1. Using a single-layer MoS2 sample, we found that the sensitivity of our system, while somewhat lower, remains within a useful range compared to commercial research-grade confocal Raman microscopy systems. This study presents a compelling solution for researchers seeking efficient and high-resolution Raman spectroscopy tools across diverse applications, particularly in resource-limited or field-based settings.