A novel Raman spectrometer using the Bessel-like laser beam for homogeneous phases and interface detections

Bessel beams, often referred to as "non-diffractive" light, have been successfully applied in numerous fields. In this study, we integrated a Bessel beam as the illumination source into a Raman spectrometer to enhance the detection of homogeneous phases and interfaces. By simulating optical path systems, we optimized the setup to fully utilize the multi-pixel array and maximize detection sensitivity. Compared to a conventional Gaussian-beam Raman spectrometer in the 90°-scattered configuration, the upgraded Raman spectrometer employing a Bessel-like beam demonstrated a nearly 6-fold improvement in sensitivity. Additionally, it significantly suppressed background scattering interferences in the low-frequency range, enhancing the clarity and accuracy of spectral data. Furthermore, the capability of this spectrometer for real-space Raman imaging of heterogeneous phase interfaces was verified. This advancement not only improves the sensitivity and precision of Raman measurements but also expands the potential applications of Raman spectroscopy in studying complex systems, such as interfaces and phase boundaries, with high spatial and spectral resolution.