Displacement detection apparatus, polarization beam splitter, and diffraction grating
US7738112B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 19, 2007 |
| Grant date | Jun 15, 2010 |
| Priority date | — |
| Expiry date | Nov 13, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/345
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A displacement detection apparatus, polarization beam splitter, and diffraction grating are provided. A displacement detection apparatus configured to detect a displacement includes a light source, a reflective diffraction grating configured to receive the two polarized beams, two polarization altering elements configured to alter the polarization states of two diffracted beams of the two polarized beams obtained at the diffraction grating, two mirrors configured to reflect the beams whose polarization states have been altered at the two polarization altering elements and to guide the reflected beams to the two polarization altering elements, each of the mirrors corresponding to the polarization altering elements, and a polarization beam splitter provided as a unit with at least the two polarization altering elements, the polarization beam splitter including a polarizing and splitting surface and a transmissive area.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.