20090310634 | STABILIZED LASER SOURCE WITH VERY HIGH RELATIVE FEEDBACK AND NARROW BANDWIDTH - This invention relates to the stabilization of a laser source used in opto-electronics, specifically a source comprising a semiconductor laser diode. Such laser sources are often used as so-called pump lasers for fiber amplifiers in the field of optical communication, erbium-doped fiber amplifiers being a prominent example. Such lasers are usually designed to provide a narrow-bandwidth optical radiation with a stable power output in a given frequency band. The present invention now concerns such a laser source using external reflector means, preferably consisting of one or more appropriately designed fiber Bragg gratings, providing very high relative feedback with an extremely narrow bandwidth, combined with a very long external cavity encompassing about 100 modes or more and an extremely low front facet reflectivity of the laser diode. Also, the FWHM bandwidth of the external reflector is selected to be significantly smaller than the distance between the modes within the laser diode. This stabilizes the laser source extremely well in its operation, even without an active temperature stabilizing element. | 12-17-2009 |