A new kind of measure and control system for high power CO<sub>2</sub> lasers in real-time is designed in order to improve
stabilization and accuracy of lasers power, and includes tow parts, one is the sample unit, made of a rear mirror, an
integrating sphere and an infrared detector, the other one is the and feedback control unit made of a PID controller. This
system adjusts output power of the lasers and makes the laser power stable in the required scope by the closed-loop
control system according to the feedback of laser power signal, which depends on the sampling of laser power
transmitted out of the rear mirror of the resonator. This system can detect and monitor the laser power on line and has no
influence on the output laser beam. It greatly enhances the stabilization (<±0.3%) and accuracy of the control.
Furthermore, it has such advantages as: compact construction, high stable performance and fast response and no need to
intercept the output laser beam just as the monitor with rotating pin sampling.