Laser diode pumped solid-state laser oscillator and laser diode control method of the oscillator

Abstract

Plural LDsare series-connected and pump a solid-state pumping medium. Each of bypass circuitsis connected in parallel to an associated one of the LDs. An operation of driving each of the bypass circuitsis controlled by a control circuit. A detection circuitis provided corresponding to each of the LDsand detects a short circuit failure and an open failure of each of the LDsaccording to a voltage developed thereacross or the like. The detection circuitand the control circuitare connected to and are controlled by an LD shortcircuit control circuit. In a case where a failure of the LD is detected by the detection circuit, the LD shortcircuit control unitdetermines the position of the failed LD to bypass electric current having flowed through the failed LD. Then, the control circuitsends a signal to a predetermined control circuitto thereby operate a predetermined bypass circuit. The LD shortcircuit control unitdetermines the position of the LD, which is to be turned off, according to the position of the failed LD to improve a pointing deviation in the solid-state medium. Then, the control unitsends a signal to the control circuitto turn off this LD. Thus, the control unitcauses a predetermined bypass circuitto operate thereby to turn off the predetermined LD.