| 摘要 |
<p>PURPOSE:To enable measurement of intensity of light in terms of reflection factor and transmissivity at a high accuracy without increase in the number of parts, by arranging a reflecting mirror, first and second photo detectors and the like. CONSTITUTION:Optical path of a laser light 2 released from a laser oscillator 1 is provided with a reflecting mirror 10 and a high reflecting surface 11 is formed on the back of the reflecting mirror 10. The laser light 2 is divided into two optical paths, one 14 which reflects the light by about 10% on an incident surface 12 thereof and the other 13 which reflects about remaining 90% thereof on the high reflecting surface 11 thereof. Moreover, the optical path 13 is provided with a reflecting mirror 3 to be measured and light from the optical path 13 is incident into a first photo detector 15 while that from the optical path 14 into a second photo detector 17 provided near the reflecting mirror 3. Then, the intensity of the laser light of the optical path 13 is measured with the detector 15 shifted to a position 16 and at the same time, the intensity of the laser light of the optical path 14 with the detector 17. This enables measurement of the intensity of light at a high accuracy in terms of reflection factor and transmissivity without increase in the number of parts.</p> |
