| 摘要 |
PURPOSE:To monitor the power of an outgoing laser by monitoring a beam leaking from a rear end of a gas laser. CONSTITUTION:A laser beam 2 which is excited by being pumped comes out from a front face 1A of a gas laser apparatus 1. A leakage laser beam 3 whose power is extremely low at about 0.2-0.3% of the power of the outgoing laser beam 2 comes out from a rear face 1B of this gas laser apparatus 1. A light detector 4 to monitor the light quantity of this leakage laser beam 3 is arranged on a light path and its output is input to a monitoring system 5. The monitoring system 5 outputs a monitoring signal which is necessary for feedback in order to make a fluctuation in the power of the gas laser apparatus 1 definite or for control in order to correct an influence due to the fluctuation in the power according to the fluctuation of the power on the side of a system to make use of the power. By this setup, it is possible to monitor the power of the laser beam without any loss of the power of the outgoing laser beam 2. |
