Miniaturized high-resolution dual 2D MEMS mirror scanning confocal Raman microscopy for topographic and Raman mapping

A novel dual 2D MEMS mirror scanning confocal Raman microscopy (D-2D-MEMS-CRM) method is proposed to realize the miniaturized design of the confocal Raman microscopy. This method uses two 2D MEMS mirrors to realize beam telecentric scanning, which eliminates the relay system consisting of a scan lens and tube lens, significantly shortens the optical length of the system, and improves the detection efficiency of Raman signal. Moreover, this method uses reflected light to construct a real-time focus tracking system, which improves the spatial resolution of the confocal Raman detection system. Based on this method, a miniaturized D-2D-MEMSCRM system was established, which had an axial focusing capability of 50 nm using an objective lens with NA of 0.6, and the lateral resolution of 500 nm for both topographic and Raman mapping. In addition, the system achieved simultaneous topographic imaging and Raman mapping of carbonaceous chondrite, demonstrating its effectiveness in extraterrestrial sample detection.