Electro-optic pulse cutting and mode-locked pulse selection at 1.315 mu m using Krytron switching

Abstract

Describes an electro-optic shutter developed to overcome specific problems for operating at the 1.315 mu m wavelength of the atomic iodine laser. The all-electronic system, using Krypton switches, features very short trigger delays (12 ns), variable gate width (5 to 25 ns) and a high transmission (95%). Emphasis has been placed on avoiding unwanted voltage loss due to internal resistance of the Krytrons, allowing the 9 kV half-wave voltage of the Pockels cell at 1.3 mu m to be attained, within the limited DC voltage rating of the Krytrons. Triggering is by a regenerative, germanium phototransistor, and a threshold discriminating avalanche transistor pulser, giving synchronisation with mode-locked laser pulses of +or-1 ns, despite large variations in the trigger pulse amplitude. The system has been applied to a high power oscillator-amplifier system for coherent interaction studies in amplifiers and absorbers.