Laser alignment servo method and apparatus
US4939739A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 24, 1989 |
| Grant date | Jul 3, 1990 |
| Priority date | — |
| Expiry date | Apr 24, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S3/139
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A servo alignment method and apparatus for maintaining laser beam alignment. An operating parameter of the laser (such as output beam power) is measured, and error signals are generated from the measured operating parameter signal for controlling the laser beam alignment. In one class of embodiments, modulation signals are supplied to an intra-cavity component of a laser system to modulated the beam path. The beam path may be modulated by reciprocating a laser resonator mirror about a mirror axis or two substantially orthogonal mirror axes. In the latter case, the mirror may be vibrated about the axes either alternately (first about one axis and then about the other) or simultaneously. In embodiments in which an intra-cavity component is modulated, the laser operating parameter is measured during such modulation, the measured operating parameter signal is demodulated (preferably by multiplication in a mixer with a selected frequency component of the modulation signal currently being asserted), and error signals are generated from the demodulated signal for controlling the laser beam alignment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.