2.94 /spl mu/m Er:YAG laser Q-switched with RTP Pockels cell

In our work for the first time we have used a Q-switch based on RTP (RbTiOPO/sub 4/) crystal in the Er:YAG laser operating at 2.94 /spl mu/m. This crystal is characterized by an excellent transparency up to 4.3 /spl mu/m, high electrical resistivity. Moreover, it is temperature stable, is not hygroscopic and does not show piezoelectric ringing. These features cause that RTP is an ideal candidate as the effective Q-switch for Er:YAG laser. A thermally compensated (double crystal) RTP Pockels cell, in a quarter-wave configuration, operating in a transverse electrode orientation with the light propagating along the optical axis was applied in our laser. One preliminary experiment of the interaction of 2.94 /spl mu/m giant laser pulses with the biological tissue was carried out. None of the thermal effects was observed in this case whereas significant coagulation was noticeable when the laser operated in free running regime.