Structures described herein may include mechanically bonded interlayers for formation between a first Group III-V semiconductor layer and a second semiconductor layer. The mechanically bonded interlayers provide reduced lattice strain by strain balancing between the Group III-V semiconductor layer and the second semiconductor layer, which may be silicon.

A class of erbium-doped silicate crystals have a general chemical formula of (Er.sub.xYb.sub.yCe.sub.zA.sub.(1-x-y-z)).sub.3RM.sub.3Si.sub.2O.sub.14, in which the range of x is 0.002 to 0.02, y is 0.005 to 0.1, and z is 0 to 0.15; A is one, two or three elements selected from Ca, Sr, or Ba; R is one or two elements selected from Nb or Ta; M is one or two elements selected from Al or Ga. Using one of such crystals as a gain medium and a diode laser at 940 nm or 980 nm as a pumping source, a 1.5 μm continuous-wave solid-state laser with high output power and high efficiency, as well as a pulse solid-state laser with high energy and narrow width can be obtained.

Systems and methods described herein may include a first semiconductor layer with a first lattice constant, a rare earth pnictide buffer epitaxially grown over the first semiconductor, wherein a first region of the rare earth pnictide buffer adjacent to the first semiconductor has a net strain that is less than 1%, a second semiconductor layer epitaxially grown over the rare earth pnictide buffer, wherein a second region of the rare earth pnictide buffer adjacent to the second semiconductor has a net strain that is a desired strain, and wherein the rare earth pnictide buffer may comprise one or more rare earth elements and one or more Group V elements. In some examples, the desired strain is approximately zero.

A seed unit (MO) includes a plurality of optical paths sharing a part thereof and causing light to be resonated thereon, an amplification optical fiber (13) serving as a part of each of the optical paths and amplifying respective light beams resonated on the respective optical paths, and; an AOM (14) arranged at a part shared by the respective optical paths and switchable between a first state, in which the AOM (14) vibrates at a predetermined cycle and emits light incident from the optical paths to the optical paths, and a second state, in which the AOM (14) emits light incident from the optical paths to a path other than the optical paths. A resonance cycle of light having highest power out of the light beams resonated on the optical paths and the predetermined cycle at which the AOM (14) vibrates in the first state have a non-integral multiple relationship.

A class of erbium-doped silicate crystals have a general chemical formula of (Er.sub.xYb.sub.yCe.sub.zA.sub.(1-x-y-z)).sub.3RM.sub.3Si.sub.2O.sub.14, in which the range of x is 0.002 to 0.02, y is 0.005 to 0.1, and z is 0 to 0.15; A is one, two or three elements selected from Ca, Sr, or Ba; R is one or two elements selected from Nb or Ta; M is one or two elements selected from Al or Ga. Using one of such crystals as a gain medium and a diode laser at 940 nm or 980 nm as a pumping source, a 1.5 m continuous-wave solid-state laser with high output power and high efficiency, as well as a pulse solid-state laser with high energy and narrow width can be obtained.

A method of making a porous three-dimensional object. The method comprises: a) positioning a first layer of particles on a build plate; b) heating the first layer of particles sufficiently to fuse the particles together to form a first build layer having a first porosity; c) exposing the first build layer to a laser beam to form one or more pores, the exposed first build layer having a first modified porosity, the laser beam being emitted from an optical fiber; d) adjusting one or more beam characteristics of the laser beam prior to or during the exposing of the first build layer, the adjusting of the laser beam occurring prior to the laser beam being emitted from the optical fiber; e) positioning an additional layer of particles on the exposed first build layer; f) heating the additional layer of particles sufficiently to fuse the particles together to form a second build layer having a second porosity; g) exposing the second build layer to the laser beam to form one or more pores, the exposed second build layer having a second modified porosity, the laser beam being emitted from the optical fiber; h) adjusting one or more beam characteristics of the laser beam after fusing the particles to form the second build layer and prior to or during the exposing of the second build layer, the adjusting of the laser beam occurring prior to the laser beam being emitted from the optical fiber, and i) repeating e), f), optionally g) and optionally h) to form a three-dimensional object.

A structure can include a III-N layer with a first lattice constant, a first rare earth pnictide layer with a second lattice constant epitaxially grown over the III-N layer, a second rare earth pnictide layer with a third lattice constant epitaxially grown over the first rare earth pnictide layer, and a semiconductor layer with a fourth lattice constant epitaxially grown over the second rare earth pnictide layer. A first difference between the first lattice constant and the second lattice constant and a second difference between the third lattice constant and the fourth lattice constant are less than one percent.

Systems and methods for end pumped laser mirror stack assemblies are provided. In one embodiment, an end pump mirror stack assembly for a laser resonator comprises: a pump light injection layer applied to a transparent substrate, the pump light injection layer comprising at least one light generating optical emitter embedded within the pump light injection layer, wherein the pump light injection layer is configured to transmit a pump light having a first wavelength into the substrate; a multilayer thin-film mirror stack coupled to the transparent substrate; a lasing material layer coupled transparent substrate and positioned to receive the pump light, wherein the lasing material layer is doped with a dopant that generates a fluorescent light output at a second frequency when exposed to the pump light; and an antireflective coating applied to the substrate, the first anti-reflective coating configured to pass light of the first wavelength.

A seed unit (MO) includes a plurality of optical paths sharing a part thereof and causing light to be resonated thereon, an amplification optical fiber (13) serving as a part of each of the optical paths and amplifying respective light beams resonated on the respective optical paths, and; an AOM (14) arranged at a part shared by the respective optical paths and switchable between a first state, in which the AOM (14) vibrates at a predetermined cycle and emits light incident from the optical paths to the optical paths, and a second state, in which the AOM (14) emits light incident from the optical paths to a path other than the optical paths. A resonance cycle of light having highest power out of the light beams resonated on the optical paths and the predetermined cycle at which the AOM (14) vibrates in the first state have a non-integral multiple relationship.

Systems and methods described herein may include a first semiconductor layer with a first lattice constant, a rare earth pnictide buffer epitaxially grown over the first semiconductor, wherein a first region of the rare earth pnictide buffer adjacent to the first semiconductor has a net strain that is less than 1%, a second semiconductor layer epitaxially grown over the rare earth pnictide buffer, wherein a second region of the rare earth pnictide buffer adjacent to the second semiconductor has a net strain that is a desired strain, and wherein the rare earth pnictide buffer may comprise one or more rare earth elements and one or more Group V elements. In some examples, the desired strain is approximately zero.