Optical design of near infrared fluorescence confocal laser scanning system

In order to realize the high resolution scanning for near infrared fluorescence，a laser scanning confocal optical system was designed which worked in the near infrared region.The lighting lens,and emission lens were realized based on simple concave lens and convex lens.The software Zemax was used for the optical design and simulation. Simulation results shows that the focal spot-s size of lighting lens is less than 1 m, and the focal spot-s size is less than 40 m at the lighting pinhole position, which meets the lighting pinhole-s requirement.The focal spot-s size is less than 10 m at the emission pinhole position, which meets the emission pinhole-s requirement.In addition,the cutoff frequency of the lighting lens and emission lens meets the diffraction limit resolution requirement respectively. Therefore, it has high optical transmission efficiency.