| 摘要 |
PURPOSE:To obtain a stable and accurate laser output measurement value which is not influenced by ambient temperature by combining a simple and small-scale temperature control mechanism and a temperature compensation mechanism. CONSTITUTION:The light path of laser beams LB entering a housing 12 is bent by 90 degrees by a reflection mirror 14 and is applied to the light reception surface of a photodiode 46 through a glass plate 36, a light diffusion plate 40, an ND filter 42, and a visible light breaking filter 44. The optical filters 42 and 44 and the photodiode 46 are retained in one piece to a second retaining body 28 with an improved heat conductivity. The temperature of the second retaining body 28 is set to a set temperature by a temperature control mechanism consisting of an electrical heating element, a temperature sensor, and a temperature control circuit. An electrical signal obtained from the photodiode 46 is corrected by temperature compensation. |
