ONE TO TEN GHZ PULSE RATE MODE-LOCKED LASERS

SHORT PULSED LASERS FOCUSED TO SMALL SPOT SIZES HAVE HIGH FIELD STRENGTHS THAT SHOW PROMISE FOR APPLICATIONS NECESSARYFOR DRIVING HIGH ACCELERATION GRADIENT AND HIGH EFFICIENCY PARTICLE ACCELATORS. APPLICATIONS INCLUDE GENERATING SHORT PULSES OF ELECTRONS ON PHOTOCATHODES FOR PLASMA ACCELERATORSAND FREE ELECTRON LASERS, BEAT WAVE ACCELERATOR EXPERIMENTS,AND PRECISE SWITCHING OF POWER LINACS. THIS PROJECT FOCUSESON APPLICATIONS REQUIRING PULSE RATES IN THE GIGAHERTZ RANGE, SUCH AS THE LASERTRON CONCEPT. OPTICAL PULSES WITH PULSEWIDTHS 1/10 THE PULSE INTERVAL OR LESS AT WAVELENGTHS NEAR ONE MICRON WITH SYSTEM EFFICIENCIES GREATER THAN 10% SATISFY THE SYSTEM REQUIREMENTS OF MANY SUCH APPLICATIONS. THIS PROJECT WILL BUILD AND EVALUATE A 2 GHZ PULSE RATE, DIODE-PUMPED, MODE-LOCKED ND:YLF LASER. THE HIGH PULSE RATEIS ACHIEVED USING A NOVEL HIGH- FREQUENCY, HIGH-DIFFRACTION EFFICIENCY ACOUSTO-OPTIC MODULATOR. PULSEWIDTHS ARE EXPECTED TO BE LESS THAN 1/10 THE PULSE INTERVAL, POSSIBLY SHORTER THAN 10 PS, WITH AN AVERAGE POWER GREATER THAN 100 MW. AT LESS DRIVE POWER TO THE MODELOCKER, THE PULSEWIDTH COULD BE INCREASED IF DESIRED. DIODE LASER PUMPING PERMITS HIGHLY EFFICIENT, LONG-LIVED, AND HIGHLY RELIABLE OPERATION OF THIS SYSTEM.