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As the continual improvement of technology and beam quality, diode laser, with poor beam quality, no longer just apply
to pump solid-state laser. As a kind of implement of laser materials processing, high-power diode laser has been used in
manufacture, as a brand new means of laser processing. Due to the influence of inevitable unstable factors, for example,
the temperature of water-cooler, the current of power supply, etc, the output power of diode laser will be unstable. And
laser output power, as an important parameter, frequently affects the performance of the laser beam and the
experimental results of processing, especially in the laser materials processing. Therefore, researching the real-time
power measurement and control of high power diode laser has great significance, and for diode laser, it would improve
performance of itself. To achieve the purpose of real-time detection, traditional measuring method, placing a power
sensor behind the total-reflection mirror of laser resonant cavity, is mainly applied in the system of gas laser and
solid-state laser. However, Owing to the high integration level of diode laser, traditional measuring method can't be
adopted. A technique for real-time measure output power of high power diode laser is developed to improve quality of
the laser in this paper. A lens placed at an angle of 45° in the system was used to sample output light of laser, and a
piece of ground glass was used to uniform the beam power density, then the photoelectric detector received an optic
signal and converted it into electric signal. This feeble signal was processed by amplification circuit with a filter. Finally,
this detected electric signal was applied to accomplish the closed-loop control of power. The performance of power
measurement and control system was tested with the 300W diode laser, and the measuring inaccuracy achieved was less
than ±1%.
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