Patent ID: 6914720

Claim:
A time-resolved fluorescence microscope comprising: a pin hole; a sample stage on which a sample is mounted; an objective lens system for projecting a reduced-size image of the pin hole on the sample on the sample stage while focusing fluorescence emitted by the sample at the pin hole; pulsed-laser emitting means; light-dividing means for dividing laser light emitted by the pulsed-laser emitting means into two portions; means for causing one portion of the laser light divided by the light-dividing means to enter the pin hole as a sample excitation light; optical-path length varying means for varying the optical path of the other portion of the laser light divided by the light-dividing means; a non-linear optical element for mixing the fluorescence from the sample exiting from the pin hole and the laser light that has passed through the optical-path length varying means to produce a sum frequency light; spectroscope means for analyzing the sum frequency light produced by the non-linear optical element to spectroscopy; a detector for detecting light emerging from the spectroscope means; and recording means for recording an output obtained from the detector as the optical path length of the other portion of the laser light is varied by the optical-path length varying means.