In the common laser microscope, the wide field light source and the laser light source have different requirements for the filter, which are mainly shown in the following aspects:
1. The laser has good monochromaticity and requires a narrow band of excitation plates;
2. Generally, experiments have certain requirements for the quality of the reflected laser beam. The dichroic mirror used needs better flatness to minimize the wavefront reflection distortion of the laser;
3. The laser energy density is high, and the emitter needs a higher cut-off depth (OD value) to reduce the excitation noise of the laser.