ACTIVE AND PASSIVE Q-SWITCHING OF A 2.79 MU-M ER-CR-YSGG LASER

Active and passive Q-switched operation of the Er: Cr: YSGG laser at a wavelength of lambda = 2.79 mum has been achieved using three different shutters. Passive switching was obtained using InAs-layers as saturable absorbers, active switching was performed electrooptically and with the FTIR (frustrated total internal reflection) technique. Single giant pulses with output energies up to 34 mJ and pulse widths of 35 ns at fwhm were achieved. InAs-layers were also used as output mirrors for passive Q-switching. In this way bursts of multiple giant pulses were generated (27 mJ in 9 pulses with pulse widths from 89 to 130 ns at fwhm). The different Q-switches were compared with regard to their applicability to medical surgery.