Drift tracking in an electro-optic light modulator
US5149953A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 24, 1990 |
| Grant date | Sep 22, 1992 |
| Priority date | — |
| Expiry date | Dec 24, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/0555
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Compensation for space charge build-up in an electro-optic modulator device is realized by recurrently recalibrating the device. During each recalibration interval, light transmitted through the device is intercepted and converted to an electric signal which is compared to a test signal of a magnitude corresponding to light of an intensity that would be transmitted through the device in the absence of space charge. The difference between the respective magnitudes of the test signal and the electric signal serves as a bias to supplement the normal modulating drive signal until the time of next recalibration. Recurrently, but at a rate lower than the recalibration rate, the device is short circuited, while flooded with light, to eliminate space charge build-up.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.