Dual feedback path linearization of galvanometer-scanned laser with a laser beam splitter housing assembly having beam shaping optics
US5371360A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 6, 1993 |
| Grant date | Dec 6, 1994 |
| Priority date | — |
| Expiry date | Dec 6, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/0264
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A laser driver mechanism for image reproduction maintains linear operation over a wide frequency an dynamic range of amplitude-modulated input signals by means of a first feedback loop and a second feedback loop. The second feedback loop contains a first amplifier coupled to receive the input signals and an output coupled to a second amplifier that drives an injection laser diode. A photodetector is coupled downstream of and external to a sealed unit in which the injection laser diode emitter, an associated photodetector of the first feedback loop and beam extraction optics are housed. The photodetector of the second loop has an output coupled to the second amplifier, so that the second feedback loop serves to compensate for non-linearities in the laser driver including those of the first feedback loop. Because the second photodetector is supported externally of the sealed unit, the feedback path from the second photodetector effectively forms an outer loop feedback path relative to the first feedback path, so that the ambient operating conditions of the second photodetector are not affected by the operation of the laser. The sealed unit is mounted in a module that effectively equa…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.