Abstract: Coherent light sources combining a semiconductor optical source with a light diverging region, such as a flared resonator type laser diode or flared amplifier type MOPA, with a single lens adapted to correct the astigmatism of the light beam emitted from the source is disclosed. The lens has an acircular cylindrical or toroidal first surface and an aspheric or binary diffractive second surface. The first surface has a curvature chosen to substantially equalize the lateral and transverse divergences of the astigmatic beam. Sources with an array of light diverging regions producing an array of astigmatic beams and a single astigmatism-correcting lens array aligned with the beams are also disclosed. The single beam source can be used in systems with frequency converting nonlinear optics. The array source can be stacked with other arrays to produce very high output powers with high brightness.

Abstract: A diode laser source including a laser diode whose emitting element array or elements or subarray is divided into a plurality of concurrently driven laser segments. Beam filling and focusing optics are disposed in front of the segments so that light from the segments in each element or subarray converges to a single overlapping spot. The optics include a beam filling lens array collimating the light from the segments and either a single focusing lens or a second lens array focusing the collimated light to corresponding spots. In the case of a element laser diode array, each multi-segment element or subarray of the array is individually addressable so as to be driven independently from the other multi-elements array elements. The segmentation of laser elements improves laser life by reducing thermal gradients and isolating any local failures to a single segment, while separately focusing of the segments of each subarray to overlapping light spots increases the tolerance of the source to local failures.

Abstract: A method of producing a high power and brightness beam from diode laser source that either has a single emitting element or array with a plurality of segments or emitters that are concurrently addressable, or has a plurality of elements or subarrays each having a plurality of laser segments or emitters, which elements or subarrays are independently addressable relative to one another. Beam filling and focusing optics are disposed in front of the emitters so that light from the individual emitters from each subarray converge to from a single overlapping spot. Segmentation of laser subarrays and emitters improves laser life by reducing thermal gradients and isolating any local failures to a single segment emitters, while the focusing of the segments or emitters to overlapping light spots increases the tolerance of the source to local failures. Two or more emitters in a given element must fail before the source is considered to have failed.

Abstract: Coherent light sources combining a semiconductor optical source with a light diverging region, such as a flared resonator type laser diode or flared amplifier type MOPA, with a single lens adapted to correct the astigmatism of the light beam emitted from the source is disclosed. The lens has an acircular cylindrical or toroidal first surface and an aspheric or binary diffractive second surface. The first surface has a curvature chosen to substantially equalize the lateral and transverse divergences of the astigmatic beam. Sources with an array of light diverging regions producing an array of astigmatic beams and a single astigmatism-correcting lens array aligned with the beams are also disclosed. The single beam source can be used in systems with frequency converting nonlinear optics. The array source can be stacked with other arrays to produce very high output powers with high brightness.

Abstract: In an optical transmission medium, such as a fiber amplifier, two optically distinguishable signals with complementary modulation are both inputted into the amplifying medium for encoding information, particularly a serial stream of digital data, or alternatively, redundant encoding of pulses. The gain profile in the medium is preferably maintained approximately constant at all times, so that whichever amplified signal is used as the primary information carrier, its output intensity will be substantially stable from pulse to pulse, independent of recent pulse history. The two complementary signals may have different orthogonal linear polarizations or wavelengths with the same stimulated emission cross-section, so that the population inversion profile stays constant, whichever signal happens to be on at a given moment.

Abstract: A diode laser source including a laser diode whose emitting element or elements is divided into a plurality of concurrently driven laser segments. Beam filling and focusing optics are disposed in front of the segments so that light from the segments in each element converges to a single overlapping spot. The optics include a beam filling lens array collimating the light from the segments and either a single focusing lens or a second lens array focusing the collimated light to corresponding spots. In the case of a multi-element laser diode array, each multi-segment element of the array is individually addressable so as to be driven independently from the other array elements. The segmentation of laser elements improves laser life by reducing thermal gradients and isolating any local failures to a single segment, while the focusing of the segments to overlapping light spots increases the tolerance of the source to local failures.

Abstract: A semiconductor laser that includes a monolithic submount with a light emitting source aligned along one side thereby defining a radiation path over which the emitted light propagates. The submount includes two notches that flank the light emitting source. A micro-lens is mounted adjacent to the light emitting source by attaching to the submount with either epoxy or solder. Finally, the components of the semiconductor laser have matching coefficients of thermal expansion so that the optical alignment of the light emitting source and the micro-lens is maintained notwithstanding thermal cycling.

Abstract: A laser diode package incorporating a first laser diode (or diode laser array) for providing a modulated light output and a second laser diode (or diode laser array) with substantially similar thermal operating characteristics which is modulated with a complementary current signal relative to the modulated current signal driving the first laser diode. The two laser diodes are mounted in close proximity to one another on a temperature controlled heat sink. For diode laser arrays, slots are provided in the heat sink between adjacent array elements. The complementary modulation of corresponding elements in each laser diode ensures that the combined heat generation by each such corresponding pair of elements is constant in time. In the case of digital modulation, the driver logic and current drivers providing the complementary modulation signals may be a modulation controlled switch routing a constant current to one or the other of each corresponding pair of laser elements.

Abstract: An optical system for use in conjunction with a one or two dimensional array of high brightness sources where such sources are individually rotated by multiple reflective elements and in turn may be captured by beam filling optics and subsequently re-imaged by symmetric and asymmetric optics where the asymmetric optics preferentially image a single dimension while leaving the focus in the second dimension largely unaffected. In this manner and by properly selecting the spacing as well as the width of the line sources, and by properly designing the symmetric and asymmetric optics, the array of high brightness sources can be reformatted in a brightness conserving manner that allows the reformatted beam to simultaneously have an arbitrary ratio of image length to image width and arbitrary divergences in the respective dimensions.

Abstract: Semiconductor heterostructure lasers having at least one lattice mismatched strain layer in the cladding proximate to the active region. Indium or phosphorus may be added in high concentration to form the strain layers. The strain layers may be spaced somewhat apart from the active region or may be adjacent to the active region. In either case, the strain layers decrease transparency current and increase differential gain.

Abstract: GaAs/AlGaAs heterostructure lasers containing indium in at least one layer other than or in addition to the active region. Embodiments are described in which indium added in low concentration to the cladding functions to match the lattice constants between the cladding and active layers, in which indium is added in high concentration to form strain layers that prevent defect migration therethrough and if proximate to the active region decrease transparency current and increase differential gain, in which indium is added uniformly to all layers to suppress defect formation, and in which indium is added to a cap layer to reduce metallization contact resistance.