| 摘要 |
PURPOSE:To measure an accurate absolute reflection factor by separating a reflected light beam from a measurement light beam by using a polarization beam splitter and a quarter-wavelength plate. CONSTITUTION:A light beam from a light source 1 is incident on a chopper 3 which rotates around a shaft 4 at an equal speed through a plane mirror 2. Part of the light is passed through the chopper 3 as the measurement light beam L1 and the remainder is reflected as a reference light beam L0. The beam L0 is reflected by plane mirrors 5 and 6 and converted 7 photoelectrically. The beam L1, on the other hand, is passed through a plane mirror 8 and a polarizer 13 to enter the polarization beam splitter 9. When a body 100 to be measured is present, the beam L1 is incident on the body 100 to be measured through the splitter 9 and quarter-wavelength plate 10 and the reflected beam from the measured surface is passed through the plate 10, splitter 9, and plane mirrors 14 and 16 and converted 7 photoelectrically. Further, when there is not the objective body 100, the beam L1 is passed through the quarter-wavelength plate 11, polarization beam splitter 12, and plane mirrors 15 and 16 and converted 7 photoelectrically. Thus, the accurate absolute reflection factor is measured from the intensity of the reference light beam and the intensity of the reflected light beam. |
