Suppressed photocurrent, quantum well optical modulation device
US5436756A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1992 |
| Grant date | Jul 25, 1995 |
| Priority date | — |
| Expiry date | Sep 30, 2012 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB82Y20/00
- WIPO fieldMicro-structural and nano-technology
- WIPO sectorChemistry
Abstract
Photocurrent suppression is achieved without deleteriously affecting modulation performance in a surface normal, electro-absorption, quantum well modulator by introducing a sufficient number of non-radiative recombination centers in the quantum well region of the modulator. The presence of the non-radiative recombination centers significantly shortens the lifetime of photogenerated carriers and, thereby, suppresses the photocurrent. Modulation performance characteristics such as contrast ratio are maintained at acceptable levels even though exciton broadening occurs in the quantum wells. The present modulator exhibits a careful balance between defect density in the quantum wells and the acceptable degree of exciton broadening necessary to preserve quantum effects.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.