| 摘要 |
PURPOSE:To compare the intensity values of light sources speedily and accurately by providing a chopper which switch light beams from two light sources alternately and a means which compares electric signals outputted from a photodetector alternately and minimizes their difference. CONSTITUTION:The optical power meter is equipped with the chopper 17 and controller 20. The chopper 17 is arranged in the middle of a right-angled prism 9 and the 1st and the 2nd condenser lens, and performs switching operation so that the photodetector is irradiated with light beams from a reference light source and an unknown light source alternately. The controller 20 compares electric signals outputted from the photodector alternately and performs arithmetic to control the gate of an optical gate device 7 so that the difference between the electric signals is minimum. Consequently, the intensity values of the two light sources are compared eaily, speedily, and accurately without shifting the two light sources in position. |
