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 light-emitting device includes an optical amplifier and gives off output light from optical amplifier by making a plurality of seed light rays, having mutually different wavelengths, incident on optical amplifier. Optical amplifier includes a medium portion containing a wavelength-converting element. Optical amplifier has wavelength-converting element thereof excited by excitation light to produce a plurality of partially coherent light rays, of which wavelengths are respectively the same as the mutually different wavelengths of plurality of seed light rays, thereby giving off, as output light, a multi-wavelength light beam. Excitation light has a shorter wavelength than any of plurality of seed light rays and is incident on the medium portion. Multi-wavelength light beam includes a plurality of light rays amplified. Plurality of light rays amplified have wavelengths, which are respectively the same as mutually different wavelengths of plurality of seed light rays.

A method and a laser for breaking through the limitation of fluorescence spectrum on laser wavelength is disclosed. The method includes: exciting electrons to a high energy level by pump light, and suppressing an oscillation of radiation light by laser cavity coating, using a laser resonance to enhance a transition probability of an electron-phonon coupling from the high energy level to a multi-phonon coupling level, so as to realize the emission and enhancement of breakthrough fluorescence spectrum and realize the radiation light oscillation, wherein the laser cavity includes an incident mirror, a folding mirror, a tuning element and an exit mirror arranged in sequence along an optical path direction, the laser gain medium is located between an incident mirror and a folding mirror in the laser resonator, and the tuning element is arranged in the laser cavity at a Brewster angle.

A light-emitting system includes an optical fiber, a first light source unit, a second light source unit, and a light-guiding member. The optical fiber includes a wavelength-converting portion containing a wavelength-converting element. The wavelength-converting element may be excited by excitation light to produce a spontaneous emission of light having a longer wavelength than the excitation light and may also be excited by an amplified spontaneous emission of light. The first light source unit makes the excitation light incident on the optical fiber. The second light source unit makes seed light, causing the wavelength-converting element that has been excited by either the excitation light or the amplified spontaneous emission of light to produce a stimulated emission of light, incident on the optical fiber. The light-guiding member guides the light coming from the optical fiber and lets the light emerge therefrom.

In a lighting system an optical fiber includes a light incident portion, a light emerging portion, and a wavelength-converting portion. The wavelength-converting portion is provided between the light incident portion and the light emerging portion. The wavelength-converting portion contains a wavelength-converting element which is excited by excitation light and amplifies a spontaneous emission of light, having a longer wavelength than the excitation light, with an amplified spontaneous emission of light. A first light source unit makes the excitation light incident on the light incident portion. A second light source unit makes seed light, which causes the wavelength-converting element excited by the excitation light and the amplified spontaneous emission of light to produce a stimulated emission of light, incident on the light incident portion. A lighting unit, into an external space, light emerging from the light emerging portion of the optical fiber.

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.

The invention discloses a preparation method and device of active microcrystalline fiber, place the prefabricated rod in the drawing furnace for wire drawing, the drawn fiber is induced by magnetic field in uncoated state and combined with laser treatment technology, the laser beam is focused on the fiber and recrystallized after laser treatment to obtain active microcrystalline fiber. Appropriate laser processing power directly affects the silicate glass fiber in the crystal structure, type, degree of crystallinity, grain size, content, and how much residual phase of glass. Induced by external magnetic field, the thermodynamics and dynamics of crystallization process are changed, make the crystal size distribution is better and uniform, reduce the phenomenon of condensation and makes the grain size is smaller.

Laser signal intensity is resonantly enhanced within a laser cavity to be greater than a pump intensity. This enables the suppression of excited-state absorption and is applicable to terbium-doped fiber lasers, lambda-type materials, or other materials used in lasers. In other embodiments, ESA is suppressed by de-populating the higher excited state using a resonant cavity.

The invention discloses a preparation method and device of active microcrystalline fiber, place the prefabricated rod in the drawing furnace for wire drawing, the drawn fiber is induced by magnetic field in uncoated state and combined with laser treatment technology, the laser beam is focused on the fiber and recrystallized after laser treatment to obtain active microcrystalline fiber. Appropriate laser processing power directly affects the silicate glass fiber in the crystal structure, type, degree of crystallinity, grain size, content, and how much residual phase of glass. Induced by external magnetic field, the thermodynamics and dynamics of crystallization process are changed, make the crystal size distribution is better and uniform, reduce the phenomenon of condensation and makes the grain size is smaller.

A light-emitting device includes an optical fiber, a first light source unit, and a second light source unit. The optical fiber includes a wavelength converting portion. The wavelength converting portion is provided between a light incident portion and a light emerging portion. The wavelength converting portion contains a wavelength converting material. The wavelength converting material is excited by excitation light to produce a spontaneous emission of light having a longer wavelength than the excitation light and amplifies the spontaneous emission of light to produce an amplified spontaneous emission of light. The first light source unit makes the excitation light incident on the light incident portion. The second light source unit makes seed light, causing a stimulated emission of light to be produced from the wavelength converting material that has been excited by either the excitation light or the amplified spontaneous emission of light, incident on the light incident portion.