Plural LDs 6 are series-connected and pump a solid-state pumping medium 7. Each of bypass circuits 15 is connected in parallel to an associated one of the LDs 6. An operation of driving each of the bypass circuits 15 is controlled by a control circuit 14. A detection circuit 13 is provided corresponding to each of the LDs 6 and detects a short circuit failure and an open failure of each of the LDs 6 according to a voltage developed thereacross or the like. The detection circuit 13 and the control circuit 14 are connected to and are controlled by an LD shortcircuit control circuit 11. In a case where a failure of the LD is detected by the detection circuit 13, the LD shortcircuit control unit 11 determines the position of the failed LD to bypass electric current having flowed through the failed LD. Then, the control circuit 11 sends a signal to a predetermined control circuit 14 to thereby operate a predetermined bypass circuit 15. The LD shortcircuit control unit 11 determines 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 7. Then, the control unit 11 sends a signal to the control circuit 14 to turn off this LD. Thus, the control unit 11 causes a predetermined bypass circuit 15 to operate thereby to turn off the predetermined LD.