Optical multivibrator
US4685108A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 3, 1985 |
| Grant date | Aug 4, 1987 |
| Priority date | — |
| Expiry date | Jul 3, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/0683
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical square wave multivibrator includes a semiconductor laser that operates near the polarization transition temperature in a pure TM mode at low injection currents and switches operation to a pure TE mode at high injection currents, and vice versa. Near such temperature, the semiconductor laser experiences large hysteresis loops with high contrast ratio in its polarization-resolved power vs current characteristic while total power exhibits only slight change in hysteresis. The switching behavior of the TE mode is complementary to that of the TM mode. The laser is biased within the hysteresis loops. A current pulse applied in one direction to the laser causes it to provide a TE mode laser output, whereas a current pulse applied in the other direction causes the laser to provide a TM mode laser output. Optical delay line means are coupled to the laser so as to be responsive to an initiation of light in a TE mode for causing a current pulse to be applied to the laser to switch it to the TM mode laser output and to be responsive to cessation of light in the TE mode from the laser for causing a current pluse to be applied in one direction to cause the laser to switch to TE mode, …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.