Low coupling beam splitter and laser power or position monitor using same
US5002371A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 5, 1989 |
| Grant date | Mar 26, 1991 |
| Priority date | — |
| Expiry date | Oct 5, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/3066
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A low coupling beam splitter with no cross-polarization error or critical alignment tolerances is formed of a quartz piece having a first planar face in the optical path in the plane of the cross-polarization and at or near Brewster's angle to the beam. A second planar face is in the interior optical path in the plane of the cross-polarization and off of Brewster's angle to the beam, so that a majority of the component having the dominant polarization is transmitted along the optical path, while a small fraction of the component having the dominant polarization and a portion of the cross-polarized component are reflected along a first interior sample path. A third planar face is in the first interior sample path in the plane of the dominant polarization and at or near Brewster's angle to the reflected beam. Thus, a portion of the component having the dominant polarization is reflected as a sample beam, and the majority of the component having the cross-polarization is transmitted away from the sample beam. A standard photodetector can be placed in the sample path for monitoring the power or position of the beam, with no error due to the cross-polarized component.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.