MICROWAVE-EXCITED GAS LASER OSCILLATOR AND CONTROL METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To prolong the life of a magnetron and raise the rise time of a pulse in a pulse operation mode by specifying the value of the quotient of the division of the mean current by the peak current given by a magnetron current at least at a max. magnetron power. SOLUTION: A magnetron drive circuit 25 constructs a microwave generator 12 with a magnetron 6 to drive a magnetron in a pulse mode according to a signal from a controller 13. The applied voltage is varied with a const. duty of the magnetron current so that D=(mean current/peak current)×10 of the magnetron current is always over 40. The drive circuit 25 may be composed of a PEM or resonance type drive circuit which always provides the D value of the magnetron current over 40 at a max. power while the magnetron current duty ratio varies according to a signal from the controller 13.