Temporal focusing-based multiphoton excitation fluorescence microscopy system capable of tunable-wavelength excitation and excitation wavelength selection module thereof

A temporal focusing-based multiphoton excitation (MPE) fluorescence microscopy system capable of tunable-wavelength excitation, comprising:

• an excitation wavelength generation module for generating excitation light of a predetermined wavelength and thereby forming an optical path;
• an excitation wavelength selection module comprising:
• an angular adjustment unit which is a reflection device configured to rotate at a fixed point in order to reflect the excitation light;
• a control unit for driving the angular adjustment unit according to the predetermined wavelength of the excitation light in order for the excitation light to generate reflected excitation light having a predetermined output angle;
• and
• a diffraction unit for receiving the reflected excitation light and generating detecting excitation light;
• and
• a fluorescence microscope with an illuminative optical lens set having an incident end configured for receiving the detecting excitation light in order to examine a to-be-examined object;
• wherein the angular adjustment unit is rotatable at the fixed point according to the equation θm(λi)=tan−1[M×tan (sin−1(λi/a)−θc)], and the temporal focusing-based MPE fluorescence microscopy system further comprises a third beam expander provided downstream of a reflection end of the reflection device, where:
• θm(λi) is an angle of rotation of the reflection device, M is a magnification of the third beam expander, λi is a central wavelength of the excitation light, a is an effective pitch of periodic structures of the diffraction unit, and θc is an angle of incidence corresponding to an initial wavelength of the excitation light.