Laser scanning microscope with large field and high NA

Abstract

An innovative highly symmetrical laser scanning microscope using a toroidal reflective scan lens and a highly efficient, low-noise collection system based on a modified Offner configuration. The system was originally developed for applications in two-photon microscopy (TPM). The optics provide for a perfect scanning spot along an arcuate line with no off-axis aberrations. On-axis aberrations are corrected with a free-form compensator placed on the input beam. The perpendicular scanning dimension to the scan line is obtained by linearly translating the whole microscope with respect to the specimen or moving the specimen. The design examples presented are for a 30-mm scan line and an NA of 0.5, and are both refractive and all-reflective, thus with minimum dispersion to prevent pulse broadening.