Optical sectioning in multifoci Raman hyperspectral imaging

In this study, we compared the depth discrimination and speed performance of multifoci Raman hyperspectral imaging with the reference standard of a single laser point confocal Raman mapping. A liquid crystal spatial light modulator was employed for the generation of multifoci laser beams, and a digital micromirror device was used as a software‐configurable reflective pinhole array. The patterns of the laser foci and pinhole array can be rapidly changed without requiring any hardware alterations. Confocal patterns with different distance‐to‐size ratios were tested and compared. After optimization of the laser‐foci pattern, we demonstrated the feasibility of multifoci Raman hyperspectral microscopy for recording depth‐resolved molecular maps of biological cells (Acanthamoeba castellanii trophozoites). Micrometric depth discrimination and short acquisition times (20 min for single plane confocal image) were achieved.