| 摘要 |
<p>PURPOSE:To measure the reflectivity of a mirror surface caused by the vertical input of light directly, by using 1/4 wavelength plates, crossing the linearly polarized light at the incident side and the linearly polarized light on the reflecting side at a right angle, and making it possible to split the incident light and the reflected light. CONSTITUTION:Luminous flux from a light source is made to pass through a polarizer 3. The luminous flux is split into two luminous fluxes through a polarized light beam splitter 4. One luminous flux is made to pass through a 1/4 wavelength plate 5 and inputted into a sample Ms. The other is made to pass through a 1/4 wavelength plate 6 and inputted into a reference mirror Mr. The reflected light beams from the sample Ms and the reference mirror Mr are inputted into a photodetector D through the 1/4 wavelength plates 5 and 6. At this time, the incident light and the reflected light are converted into the linearly polarized lights, whose polarizing directions are crossed at a right angle each other. Therefore, the incident light and the reflected light can be readily separated. The detected signals based on the reflected light from the sample Ms and the reflected light from the reference mirror Mr are separated in a sampling circuit Sw, which is synchronized with the rotation of the polarizer 3. A control circuit C computes a relative reflectivity based on said detected signals.</p> |
