Optical polarization sensing apparatus and method
US6188477A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 4, 1999 |
| Grant date | Feb 13, 2001 |
| Priority date | — |
| Expiry date | May 4, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB82Y30/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An integrated polarization sensing apparatus and method uses a self-homodyne detection scheme to provide required sensitivity for numerous applications, such as glucose concentration monitoring, without the need for expensive, bulky components. The detection scheme is implemented by splitting a polarized laser beam with a polarization beam splitter into a P wave component and an S wave component, phase modulating the P wave component and recombining the two components. The polarization of the combined optical beam is then rotated slightly by the variable to be monitored, such as by passing the beam through a glucose solution. Finally, the beam is passed onto a photodetector that generates a signal that is proportional to the polarization rotation angle. This device has the advantage of employing optical components, including polarizing beam splitters, phase modulators and lenses, that can all be fabricated on a single silicon chip using MEMS technology so that the device can be made compact and inexpensive.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.