Abstract: An optical fiber laser has an output that is stabilized to adapt to changes in laser operating temperature. At the output of the laser a plurality of wavelength-selective stabilizing reflectors is provided, each having a reflectivity profile with a different center wavelength. The reflectors, typically Bragg gratings, have a relative degree of reflectivity and relative wavelength separation that results in the output power of the laser being at one or more of the reflector center wavelengths throughout the temperature change. Thus, as a temperature shift causes the wavelength of the optical energy generated in the laser gain medium to change, the grating-stabilized output of the laser shifts between one locked wavelength and another. However, the output remains stable over the extended wavelength range provided by the multiple reflectors. Such a laser is particularly useful in an amplifier system in which the laser is used as an optical pump source.

Abstract: An optical fiber laser has an output that is stabilized to adapt to changes in laser operating temperature. At the output of the laser a plurality of wavelength-selective stabilizing reflectors is provided, each having a reflectivity profile with a different center wavelength. The reflectors, typically Bragg gratings, have a relative degree of reflectivity and relative wavelength separation that results in the output power of the laser being at one or more of the reflector center wavelengths throughout the temperature change. Thus, as a temperature shift causes the wavelength of the optical energy generated in the laser gain medium to change, the grating-stabilized output of the laser shifts between one locked wavelength and another. However, the output remains stable over the extended wavelength range provided by the multiple reflectors. Such a laser is particularly useful in an amplifier system in which the laser is used as an optical pump source.

Abstract: A multistage optical amplifier pumping system with built-in redundant reliability for lightwave communication system provides plural levels of redundancy. A first level of redundancy deals with redundancy in the form of plural primary laser diode sources for pumping a single fiber laser pump source. A second level of redundancy deals with redundancy of a plurality of fiber laser pump sources for pumping a plurality of serially connected injection signal fiber amplifiers forming the multistage amplifier system. If one of fiber pump sources should fail, increased pumping power is available from the remaining fiber pump sources via their respectively connected amplifier stages. A third level of redundancy deals with redundancy in the employment of multiple single mode laser emitters on the same chip or bar sufficiently segmented and/or electrical isolated so as not to interfere with operation of or cause failure to adjacent or neighboring emitters on the same chip or bar.

Abstract: A power system for a laser source comprises a plurality of semiconductor lasers or at least one laser array with plurality of independently, electrically addressable emitters. A power supply is independently connected to each of the laser emitters. A fuse device is associated with each of the laser emitters so that an electrical short of any one emitter of a laser will not cause a short to or change the power supplied to other emitters of the laser source.

Abstract: An optical amplifier pumping system with built-in redundant reliability for lightwave communication system provides plural levels of redundancy. A first level of redundancy deals with redundancy in the form of plural primary laser diode sources in the lightwave communication system. A second level of redundancy deals with redundancy of multiple single mode laser emitters on the same chip or bar sufficiently segmented so as not to interfere with operation of or cause failure to adjacent or neighboring emitters on the same chip or bar. A third level of redundancy deals with redundancy of a plurality of fiber pump sources for pumping a plurality of serially connected injection signal fiber amplifiers.

Abstract: An optical amplifier pumping system with built-in redundant reliability for lightwave communication system provides plural levels of redundancy. A first level of redundancy deals with redundancy in the form of plural primary laser diode sources in the lightwave communication system. A second level of redundancy deals with redundancy of multiple single mode laser emitters on the same chip or bar sufficiently segmented so as not to interfere with operation of or cause failure to adjacent or neighboring emitters on the same chip or bar. A third level of deals with redundancy of a plurality of fiber pump sources for pumping a plurality of serially connected injection signal fiber amplifiers.

Abstract: A laser diode construction having internal reflectors within the laser cavity to provide a stable spectral mode of laser operation. The laser includes a plurality of contiguous semiconductor layers disposed on a substrate to form a semiconductor body with at least one layer forming an active region. Electrically conductive contacts bias the heterostructure to inject current into the active region and produce lightwaves. Feedback means define two or more tandem resonant optical cavities to achieve lasing operation. The feedback means includes at least one internal light reflector within the semiconductor body. In a preferred embodiment, a pair of spaced apart internal reflectors are provided with the region between the pair also being electrically pumped to define an active internal etalon. Other embodiments have multiple periodic reflectors or combine internal reflectors with feedback gratings or passive windows at the end facets of the body.

Abstract: A laser having a phase conjugating reflector positioned with a resonant cavity of a laser configuration capable of multimode operation. The resonant cavity or other means associated with the laser configuration selects the preferred mode at threshold. The phase conjugating material builds up reflectivity as the light intensity is increased above threshold power levels to maintain the selected mode to high power levels. One embodiment has an external Talbot cavity with a first mirror in a Talbot plane of a multi-emitter laser array and with the phase conjugating material at a sub-Talbot plane. Another embodiment has an external GRIN lens cavity with a far field apertured stripe mirror for threshold mode selection. The phase conjugator is placed at a high light intensity position within the cavity such as adjacent to the stripe mirror or adjacent to the laser array. The laser source may be a linear laser diode array or a 2-D surface emitting laser array.

Abstract: A monolithic integrated master oscillator power amplifier (MOPA) device including a single mode diode laser with distributed Bragg reflectors, an amplifier in tandem with the laser, lateral phase controllers and a detuned second order grating surface output coupler, all on a common substrate. The amplifier is a flared waveguide in one embodiment, and a branching network of single mode waveguides followed by an array of single mode gain waveguides in another embodiment. The diode laser is tunable by means of a separate tuning current applied to the rear Bragg reflector. Tuning the laser wavelength provides, in conjunction with the output coupler, a longitudinal steering of the output beam. The lateral phase controllers are an array of separately addressable electrodes that adjust the optical path length to compensate for phase variation in the amplifiers and also to provide lateral steering of the output beam.

Abstract: A four-pass conjugate optical amplifier system and method are disclosed in which a linear polarized optical beam is directed by various optical elements through four passes of a power amplifier, preferably a diode laser structure. The beam is phase conjugated at the optical midpoint between the second and third amplifying passes, and is controlled by the optical elements so that its polarization is substantially the same during the first and second passes, and again substantially the same during the third and fourth amplifying passes. This is accomplished by a reflective coating on the back facet of the diode laser structure, with a non-reciprocal polarization rotation element located in the beam path between the phase conjugate mirror and power amplifier. For considerably enhanced power amplification, the beam may be divided into an array of subbeams, which are individually amplified by four passes through respective power amplifiers.

Abstract: A laser is disclosed which uses a curved spatial grating in either its reflective or output regions, or both, or distributed throughout the laser resonator, to produce an unstable optical reflection pattern which fills the resonating cavity more efficiently than in prior devices. Various combinations of different grating curvatures are disclosed. The invention is particularly adapted to semiconductor lasers.