| 摘要 |
PROBLEM TO BE SOLVED: To miniaturize a device by forming a semiconductor laser, a photodiode and the first to third film-like optical wave guides on the means substrate, and providing a specific structure wherein reflection light and scattered light are detected and, moving amount of a sample object is measured on the basis of interference light. SOLUTION: Light beams 61 and 62 are emitted from a semiconductor laser 1, and while transferred through film-like optical wave guides 31 and 32, the light beams 62 becomes, thanks to a gap 322, the light beam having the phase difference of 90 deg.C, and becomes spectrum by a half mirror 52. The light beam 61 becomes spectrum with a half mirror 51, and a part of it hits a sample object 7 and then enters the film-like optical wave guide 31, and then become spectrum with half mirrors 51 and 52. These spectrums are photodetected by facing photodiodes 2111 and 2112 and other photodiodes. Then in accordance with displacement of the sample object 7, the photodiodes 2112 and 2112 obtain the signals whose phases are different by 90 deg., and by comparing difference and sum of the signal each other, high precision measurement of displacement becomes possible. |
