High-speed, two-photon scanning microscope

We have developed a high-speed two-photon microscope with submicrometer res olution in real time. The imaging speed improvement of this system is obtai ned by the use of a high-speed polygonal mirror scanner. The maximum achiev able scanning rate is 40 mu s/line, which is approximately 100 times faster than conventional scanning microscopes. High-resolution fluorescence image s were recorded in real time by an intensified CCD camera. Using this instr ument, we have resolved cellular architecture in three dimensions and have monitored the movements of protozoas. More important, photodamage to biolog ical specimens during video-rate imaging can be minimized with two-photon e xcitation as compared with other one-photon modalities. (C) 1999 Optical So ciety of America.