A semiconductor laser has a mirror formed in a gain chip. The mirror can be placed in the gain chip to provide a broadband reflector to support multiple lasers using the gain chip. The mirror can also be placed in the gain chip to have the semiconductor laser be more efficient or more powerful by changing an optical path length of the gain of the semiconductor laser.

Exemplary methods and apparatus may provide optical gates and optical switches using such optical gates. Each optical gate may include a semiconductor optical amplifier that is placed in a substrate. The semiconductor optical amplifier may be coupled to input and output couplers to receive and selectively output optical signals into and out of the substrate.

A vertical cavity surface-emitting laser configured to emit laser light having a wavelength of 830 nm to 910 nm includes a substrate having a main surface including GaAs, a first distributed Bragg reflector, an active layer, and a second distributed Bragg reflector. The substrate, the first distributed Bragg reflector, the active layer, and the second distributed Bragg reflector are arranged in a first axis direction intersecting the main surface. The main surface has an off angle of 6° or more with respect to a (100) plane. The active layer includes In.sub.xAl.sub.yGa.sub.1-x-yAs (0<x<1, 0≤y<1). The active layer has a strain. An absolute value of the strain is 0.5% to 1.4%.

A phosphor element includes: a phosphor part having an incident face for excitation light, an opposing face opposing the incident face, and a side face, the phosphor part converting at least a part of the excitation light incident onto the incident face into a fluorescence and emitting the fluorescence from the incident face; an integral low refractive index layer on the side face and opposing face of the phosphor part and having a refractive index lower than that of the phosphor part; and an integral reflection film covering a surface of the low refractive index layer. The area of the incident face of the phosphor part is larger than the area of the opposing face.

Gallium and nitrogen containing optical devices operable as laser diodes and methods of forming the same are disclosed. The devices include a gallium and nitrogen containing substrate member, which may be semipolar or non-polar. The devices include a chip formed from the gallium and nitrogen substrate member. The chip has a width and a length, a dimension of less than 150 microns characterizing the width of the chip. The devices have a cavity oriented substantially parallel to the length of the chip.

An optoelectronic device includes a semiconductor substrate having first and second faces. A first array of emitters are formed on the first face of the semiconductor substrate and are configured to emit respective beams of radiation through the substrate. Electrical connections are coupled to actuate selectively first and second sets of the emitters in the first array. A second array of microlenses are formed on the second face of the semiconductor substrate in respective alignment with the emitters in at least one of the first and second sets and are configured to focus the beams emitted from the emitters in the at least one of the first and second sets so that the beams are transmitted from the second face with different, respective first and second focal properties.

A light-emitting module includes a wiring substrate, first and second bases, three or more first submounts, four or more second submounts, three or more first light-emitting elements, and four or more second light-emitting elements. The first and second bases are bonded to and electrically connected to the wiring substrate. The first submounts are arranged side by side along a first alignment direction on the first base, and the second submounts are arranged side by side along a second alignment direction on the second base. A number of the second submounts is greater than a number of the first submounts by one or more. The first and second light-emitting elements are arranged respectively on the first and second submounts. A length of each of the first submounts in the first alignment direction is greater than a length of each of the second submounts in the second alignment direction.

A method and device for emitting electromagnetic radiation at high power using a gallium containing substrates such as GaN, AlN, InN, InGaN, AlGaN, and AlInGaN, is provided.

The invention may be embodied in other forms than those specifically disclosed herein without departing from itMulti-kW-class blue (400-495 nm) fiber-delivered lasers and module configurations. In embodiments, the lasers propagate laser beams having beam parameter products of <5 mm*mrad, which are used in materials processing, welding and pumping a Raman laser. In an embodiment the laser system is an integration of fiber-coupled modules, which are in turn made up of submodules. An embodiment has sub-modules having a plurality of lensed blue semiconductor gain chips with low reflectivity front facets. These are locked in wavelength with a wavelength spread of <1 nm by using volume Bragg gratings in an external cavity configuration. An embodiment has modules having of a plurality of submodules, which are combined through wavelength multiplexing with a bandwidth of <10 nm, followed by polarization beam combining. The output of each module is fiber-coupled into a low NA fiber. In an embodiment a kW-level blue laser system is realized by fiber bundling and combining multiple modules into a single output fiber.

Methods and systems for low etch pit density 6 inch semi-insulating gallium arsenide wafers may include a semi-insulating gallium arsenide single crystal wafer having a diameter of 6 inches or greater without intentional dopants for reducing dislocation density, an etch pit density of less than 1000 cm.sup.−2, and a resistivity of 1×10.sup.7 Ω-cm or more. The wafer may have an optical absorption of less than 5 cm.sup.−1 less than 4 cm.sup.−1 or less than 3 cm.sup.−1 at 940 nm wavelength. The wafer may have a carrier mobility of 3000 cm.sup.2/V-sec or higher. The wafer may have a thickness of 500 μm or greater. Electronic devices may be formed on a first surface of the wafer. The wafer may have a carrier concentration of 1.1×10.sup.7 cm.sup.−3 or less.