Microscopic observation, surgery, and stimulation of living tissues by multiphoton absorption

摘要

Submicron sized damage spots were created by multiphoton absorption of ultra-short 775nm laser pulses in collagen gel stained with fluorescent dye. Submicron nodules were formed in the collagen both near the surface and at a depth of up to 30 mm. We have shown that large numbers of pulses at low pulse energy provide well-controlled sample damage restricted to a small focal volume. The damage threshold was dependent on dye concentration but not significantly dependent on the depth. This will be useful for experiments that study laser-induced damage in living biological samples on a cellular scale and deep within the specimen.