Laser driver circuit
US6778571B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 30, 2002 |
| Grant date | Aug 17, 2004 |
| Priority date | — |
| Expiry date | Aug 30, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/0427
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A laser driver circuit includes a pair of transistors having base electrodes respectively coupled to a differential input signal. The respective collector electrodes are coupled to a first power supply rail and the respective emitter electrodes are coupled to a laser diode via respective impedances and to respective controllable current sources to provide an average modulation voltage at the more positive of the emitter electrodes. By having the transistors in an emitter follower configuration, rather than the usual collector open collector configuration, the problem of mismatch between the output impedance of the transistors and the input impedance of the laser diode is reduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.