Thermal compensation for laser diodes using active feedback
US5335239A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 17, 1993 |
| Grant date | Aug 2, 1994 |
| Priority date | — |
| Expiry date | Mar 17, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/06804
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Providing thermal compensation for laser diodes used in intensity modulated applications by using active feedback. A PIN diode serves as a laser light output sensor for the closed loop feedback system. The input from the PIN diode is convened into a voltage and then fed into a feedback amplifier. The PIN diode current is slightly dependent upon the temperature due to transmission effects of materials within the laser diode assembly. A temperature voltage signal generated by a semiconductor temperature sensor may be used as a second input to the feedback amplifier. The output of this amplifier is sampled at periodic intervals such as once a scan line, by a sample and hold amplifier. The output of the sample and hold amplifier is added to a data dependent modulated current reference in a summing amplifier. The output of the summing amplifier is the resultant sensor and provides an input reference to the laser driver integrated circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.