Displacement detection device with adjacent semiconductor diode lasers
US5141319A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 15, 1991 |
| Grant date | Aug 25, 1992 |
| Priority date | — |
| Expiry date | Nov 15, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S977/87
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A displacement detection device has a laser unit. The laser unit has two semiconductor lasers formed on a single substrate through a single process. One of the lasers has an end coated with a reflection preventing film and facing a mirror provided at the end of a cantilever. The other end of the laser is coated with a film having a high reflectance film such that a light resonator is formed together with the mirror and the high reflectance film. The other laser has both opposite ends coated with films of a high reflectance, and a light resonator is formed between the opposite ends. Two laser beams emitted from the two semiconductor lasers interfere with each other, and the resultant interference light enters the light detector. The detector detects a variation in the interference light caused by displacement of the mirror, and outputs a signal indicative of a displacement in the cantilever.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.