LASER POWER SENSOR

PROBLEM TO BE SOLVED: To provide a laser power sensor that has sufficient measurement accuracy about light reception intensity of power sensors even with a low cost.SOLUTION: A power sensor 18 includes: a sensor substrate 24 that receives monitor light 22; and a filter 26 that attenuates intensity of light of the monitor light to be received by the sensor substrate 24. The filter 26 is made up of a material in which transmittance of laser light is zero, and includes a plurality of penetration opening parts 34 in a range where the monitor light is irradiated. A total sum of an opening area of the plurality of opening parts 34 is configured to be equal to or more than 50% of an area of the irradiation range of the monitor light on the filter 26, and of the laser light with which the filter 26 is irradiated, the laser light passing through the opening part 34 is configured to be directly received by the sensor substrate 24.SELECTED DRAWING: Figure 2 【課題】低コストでありながら、パワーセンサの受光強度について十分な測定精度を有するレーザ用パワーセンサの提供。【解決手段】パワーセンサ１８は、モニタ光２２を受光するセンサ基板２４と、センサ基板２４に受光されるモニタ光の強度を減衰するフィルタ２６とを有する。フィルタ２６は、レーザ光の透過率がゼロの材料からなり、モニタ光が照射される照射範囲内に複数の貫通開口部３４を有する。複数の開口部３４の開口面積の総和は、フィルタ２６上のモニタ光の照射範囲の面積の５０％以上となっており、フィルタ２６に照射されたレーザ光のうち、開口部３４を通過したレーザ光は、センサ基板２４に直接受光されるようになっている。【選択図】図２