FREQUENCY SWEEPING PHASE-LOCKED-LOOP SYNTHESIZER POWERSUPPLY FOR CO2 WAVEGUIDE LASER

摘要

A phase-locked-loop frequency synthesizer (18) normally applies a radio frequency (RF) drive signal (DRIVE) to a CO.sub.2 waveguide laser (10) at a first frequency which is optimal for continuous laser operation. For lighting the laser (10), a voltage-controlled oscillator (26) of the synthesizer (18) is forced to sweep the frequency of the drive signal (DRIVE) downwardly from a second frequency which is higher than the first frequency, through an intermediate third frequency which is optimal for laser lighting, to the first frequency. The laser (10) is lit during the downward sweep through the third frequency, and thereafter maintained at the first frequency for continuous operation.