Abstract

Photoablation of soft and hard biological tissue probes was investigated using a q-switched ErCr:YSGG and a q-switched CrTmEr:YAG laser. The ErCr:YSGG laser emits radiation at 2.79 µm wavelength with a pulse width of 200 to 500 ns and a maximum output of 50 mJ/pulse. A new prototype TmCrEr:YAG laser emits at 2.69µm wavelength with a maximum pulse energy of 40 mJ/pulse. Pulse durations of this laser when q-switched by a rotating prism are 500 to 2500 ns depending on flashlamp pump energy. Repetition rates of 1 to 10 Hz are possible with both lasers. The 2.69 µm radiation is efficiently transmitable by low OH⁻-quartz fibers. Up to 40% of the laser energy could be transmited through a 600 µm diameter fiber of 50 cm length. The absorption length of this wavelength in water is about 10 µm in contrast to 1.5 µm of the 2.79 µm radiation and 0.7 µm of the standard 2.94 µm Er:YAG laser.

© 1992 IQEC