52results about How to "Improve wavelength conversion efficiency" patented technology

The light-emitting apparatus includes a light-emitting element, a base body having, on its upper principal surface, a placement portion for emplacing thereon the light-emitting element; a first reflecting member formed in a frame-like shape and attached to the upper principal surface of the base body so as to surround the placement portion; a second reflecting member formed in a frame-like shape and attached to the upper principal surface of the base body so as to surround the first reflecting member; a light transmitting member provided inside the second reflecting member so as to cover the light-emitting element and the first reflecting member; and a first wavelength-conversion layer for converting a wavelength of light from the light-emitting element, the first wavelength-conversion layer being provided inside the light transmitting member disposed above the light-emitting element, spaced from the first and second reflecting members.

A light-emitting apparatus provides a ceramic-made base body, a frame body, a light-emitting element, a conductor layer and a light-transmitting member. The base body has on its upper surface a mounting portion for the light-emitting element. The frame body is joined to the upper surface of the base body so as to surround the mounting portion, with its inner peripheral surface shaped into a reflection surface. The wiring conductor has its one end formed on the upper surface of the base body and electrically connected to the light-emitting element, and has another end led to a side or lower surface of the base body. The light-transmitting member is disposed inside the frame body so as to cover the light-emitting element, which contains fluorescent materials for performing wavelength conversion. The base body is so designed that ceramic crystal grains range in average particle diameter from 1 to 5 μm.

There are provided a wavelength conversion member including phosphors made of phosphor particles which are made of an oxynitride and/or a nitride and have a refractive index n₁, and a coating which coats each of the phosphor particles and has a refractive index n₂, and a medium having the phosphors dispersed therein and having a refractive index n₃, the refractive index n₂ of the coating being a value between n₃ and n₁, and a light-emitting device having the wavelength conversion member incorporated therein. It is preferable in the present invention that the coating is formed of a plurality of layers, and has its refractive index varying in a stepwise manner in a direction from a surface of each of the phosphor particles to an interface with the medium.

Proposed is an illumination device (100), comprising a light source (110) such as an LED or a laser diode, a wavelength conversion medium (120) such as a phosphor, and a periodic antenna array (300) made of a highly polarisable material such as a metal. The light source emits primary wavelength light that at least partially is converted in secondary wavelength light by the wavelength conversion medium. The periodic antenna array is positioned in close proximity to the wavelength conversion medium and functions to enhance the efficiency of the absorption and/or emission processes in the wavelength conversion medium through the coupling of the incident primary wavelength light or the emitted secondary light to surface lattice resonances that arise from the diffractive coupling of localized surface plasmon polaritons in the individual antennas of the array. This is especially advantageous for forming low étendue illumination device suitable for use in projection systems, or for controlling the directionality, the polarization, and/or the color of the secondary wavelength light.

A laser light source device 1, comprising M number of laser light sources, of which frequency is shifted from a fundamental frequency by (m−1)·a·Δω, a first laser light source section 2 and a first fiber amplifier section 4 for amplifying these laser lights, a first optical multiplexer 6 for approximately coaxially superimposing the laser lights emitted from the first fiber amplifier section 4 and emitting the laser lights, a first wavelength conversion device 9 for multiplying the frequency of the laser lights emitted from the first optical multiplexer 6 by A, M number of laser light sources, of which frequency is shifted from the fundamental frequency by (m−1)·b·Δω, a second laser light source section 3 and a second fiber amplifier section 5 for amplifying these laser lights, a second optical multiplexer 7 for approximately coaxially superimposing the laser lights emitted from the second fiber amplifier section 5 and emitting the laser lights, a second wavelength conversion device 10 for multiplying the frequency of the laser lights emitted from the second optical multiplexer 7 by B, and a third wavelength conversion device 11 for simultaneously receiving the laser lights emitted from the first and second wavelength conversion devices 9 and 10 and converting the laser lights into laser lights, of which frequency is (A+B) times the fundamental frequency, the laser light source device 1 being characterized in that the expression A·a+B·b=0 is satisfied.

The package has a base body (51) with a mounting portion for mounting a light-emitting unit. A frame body is joined to an outer edge of the body (51) to surround the portion. A wiring conductor has its one end formed on an upper surface of the base body, to electrically connect an electrode of the light emitting unit. The light transmitting unit (53) is inside the frame body to cover the light emitting unit. - Independent claims are also included for the following: - (A) a light-emitting apparatus comprising a package for housing a light emitting unit - (B) an illumination apparatus constructed by setting up a light-emitting apparatus in a predetermined arrangement.

A vertical external cavity surface emitting laser (VECSEL) in which the full-width at half maximum (FWHM) of laser light is reduced by two etalon filter layers to improve the efficiency of second harmonic (SHG) crystal is provided. The VECSEL includes: a laser chip for generating laser light; a first etalon filter layer formed on the laser chip; a second etalon filter layer that is formed on the first etalon filter layer and has a different refractive index than the first etalon filter layer; a first mirror separated from and disposed obliquely to the laser chip; a second mirror for reflecting the laser light reflected from the first mirror back to the first mirror to form a cavity with the laser chip; and an SHG crystal disposed along an optical path between the first and second mirrors and doubles the frequency of the laser light generated in the laser chip.

A light source system (200), comprises: a light-emitting device (1) for emitting a first light and a second light in sequence; a beam splitting system (2) with which the first light emitted from the light-emitting device (1) is divided into one beam in a first range of wavelength and the other beam in a second range of wavelength, respectively emitted along a first optical path and a second optical path, and also with which at least a part of the second light emitted from the light-emitting device (1) is emitted along the first optical path; a first spatial light modulator (211) for modulating the beam emitted from the beam splitting system (2) along the first optical path; a second spatial light modulator (213) for modulating the beam emitted from the beam splitting system (2) along the second optical path. The light source system (200) has the advantages of high light-emitting efficiency and low cost. A projection system comprising the aforementioned light source system (200) is also provided.

An image display element includes micro light emitting elements disposed in an array on a driving circuit substrate. An excitation light emitting element includes a main body including a compound semiconductor, a metal electrode disposed on a side of the main body located closer to the driving circuit substrate, and a transparent electrode disposed on an opposite side to the driving circuit substrate, and a light emission layer included in the main body is disposed on a side opposite to the driving circuit substrate from a center portion of the main body.

A wavelength conversion laser light source having: a laser medium which generates a fundamental wave light; a laser resonator for causing laser oscillation of the fundamental wave light; a wavelength convertor which is provided with a wavelength converting region to convert the fundamental wave light under the laser oscillation by means of the laser resonator into converted light of a different wavelength; and an excitation laser light source for exciting the laser medium, wherein the laser resonator has at least one reflecting surface which reflects the fundamental wave, and a first reflecting element which is provided on an end surface of the wavelength convertor to reflect the fundamental wave light ; the wavelength converting region is situated between the at least one reflecting surface and the first reflecting element; the wavelength convertor has a periodic first polarization reversal structure formed in the wavelength converting region, and a non-converting region formed between the first reflecting element and the wavelength converting region; and the non-converting region does not convert the fundamental wave light into the converted light.

In a wavelength converter using a nonlinear polymeric waveguide, a wavelength variable wavelength converter having a nonlinear polymeric waveguide in which insertion losses are minimized and wavelength conversion efficiencies are improved, and an optical device using the wavelength converter are provided. The wavelength converter for converting the wavelength of inputted light includes a semiconductor substrate, a first electrode formed on the semiconductor substrate, a lower cladding layer formed on the first electrode, a core layer formed on the lower cladding layer and formed of nonlinear polymer by which the wavelength of light is substantially converted by the inputted light, an upper cladding layer formed on the core layer, and a second electrode formed on the upper cladding layer, which tunes center wavelengths of the conversion by adjusting the refractive index of the core layer. The core layer includes a projected and relatively thick rib-structure, and a quasi-phase matched grating is formed in the rib.

The invention relates to a combined 1.9 mu m wavelength converter of a hollow-core photonic crystal fiber and a seal cavity. The wavelength converter comprises a laser, a polarization controller, a hydrogen steel cylinder, a seal cavity, a hollow-core photonic crystal fiber, a fiber collimator, a lens, a gas outlet, a gas inlet, a gas circulating pump, a planar mirror and a light beam splitter. The wavelength converter is characterized in that, the laser and the polarization controller constitute a light source system, and the seal cavity is arranged at the rear part of the light source system; the seal cavity is connected with the hydrogen steel cylinder provided with a pressure-reducing valve; the hollow-core photonic crystal fiber is arranged in the seal cavity; an incident end plane of the fiber is connected with the fiber collimator; the gas outlet, the gas inlet of the seal cavity are connected with the gas circulating pump; finally the lens, the planar mirror and the light beam splitter are arranged at the rear part of the seal cavity. According to the invention, through the excellent non-linear characteristics and mode transmission characteristics of the hollow-core photonic crystal fiber, and pressure intensity modulation of the hydrogen and fluidity of the hydrogen in the seal cavity, the wavelength converter has the advantages of low threshold and high conversion efficiency.

A wavelength conversion laser light source includes a fundamental wave laser light source (1) to generate a fundamental wave; a first mirror and a second mirror (4, 5), arranged so as to oppose each other; a wavelength conversion element (3) which is arranged between the first mirror and the second mirror and converts the wavelength of the fundamental wave; and a temperature control portion (8) to control the temperature of the wavelength conversion element. A portion of the fundamental wave is wavelength-converted in the wavelength conversion element, and moreover the fundamental wave which is not wavelength-converted is reflected by the first mirror and the second mirror and is repeatedly incident on the wavelength conversion element and is wavelength-converted, and the temperature control portion is arranged so as to be in contact with the wavelength conversion element, and the light quantity of the fundamental wave incident on the temperature control portion is reduced by a fundamental wave absorption portion (18).

A projector and a wavelength-converting element are disclosed. The projector includes an illumination system, a light valve and a lens. The illumination system includes a light source providing an excitation beam, and a wavelength conversion device located at a transmission path of the excitation beam. The wavelength-converting element includes a substrate having a wavelength-converting area, an optical film disposed in the wavelength-converting area of the substrate, and a fluorescent film covering the optical film and converts the excitation beam into a converting beam. The converting beam and the excitation beam constitute an illumination beam. The fluorescent film contains phosphors, wherein the phosphors having a larger particle size are distributed among or above the phosphors having a smaller particle size. The light valve converts the illumination beam into an image beam. The image beam becomes a projection beam after passing through the lens.

A high efficiency solar battery using a fluorescent substance to efficiently use incident light and thereby improve conversion efficiency. The solar battery of the present invention comprises: a front part including a front electrode and configured to receive light; a generating part disposed behind the front part to generate electricity from specific wavelengths of light incident through the front part; and a rear part disposed behind the generating part and comprising a rear electrode, wherein a first fluorescent substance is dispersed in the front part so as to absorb light having wavelengths different from the specific wavelengths, convert the absorbed light into light having the specific wavelengths, and output the converted light.

The signal light is coupled with control light that is emitted from a laser diode 3 by a WDM coupling device 2. The optical fiber 4 on one end of the WDM coupling device is mode-matched with the optical waveguide of the quasi-phase matched quartz crystal 1 by a V groove 1a. The output light generated by the difference frequency generation of the signal light and control light is again guided to the optical fiber 5 from the quasi-phase matched quartz crystal 1 by the other V groove 1a. Then, this light is incident on the optical filter 7, so that the signal light and control light are cut. The optical fiber 9 is connected to a fiber amplifier 10. In cases where a quasi-phase matched quartz crystal is used as the wavelength conversion element, the wavelength conversion efficiency drops compared to lithium niobate as a result of the nonlinear constants being small. The fiber amplifier 10 is installed in order to compensate for this. As a result, a wavelength converter for use in optical communications can be obtained which shows little problem of optical damage, which can be used at a broad range of temperatures, and which also has good coupling characteristics with quartz type optical fibers.

The invention discloses a cascade sum-frequency and difference-frequency all-optical wavelength converter and a conversion method. After second pump light of a second laser device of the converter is transmitted through a polarization controller, a linearly polarized light conversion device and a first optical coupler, the second pump light and signal light access a second optical coupler, an erbium-doped fiber amplifier and an optical circulator together and reach a PPLN (periodically poled lithium niobate) ridge waveguide, forward light beams are reflected by a Faraday 90-degree rotating reflector, backward light beams are transmitted into the ridge waveguide, and converted idler-frequency light is outputted from the optical circulator. The conversion method includes adjusting the pump light into a TM (transverse magnetic) mode by the polarization controller, and then converting the pump light into linearly polarized light by the online polarized light conversion device; decomposing the linearly polarized light into light in a TE (transverse electric) mode and light in a TM mode in the ridge waveguide; enabling the pump light in the TM mode and the signal light in a TM mode to perform cascade sum-frequency and difference-frequency reaction and generating the converted idler-frequency light in a TM mode; reflecting other forward light and converting a mode of the other forward light by the aid of the Faraday reflector; returning the other forward light to the ridge waveguide. The polarization direction of the linearly polarized light is parallel to the cross section of the PPLN ridge waveguide, and an angle theta is formed between the linearly polarized light and an X-axis. An amplitude ratio of the light in the TE mode to the light in the TM mode is tg theta. The cascade sum-frequency and difference-frequency all-optical wavelength converter and the conversion method have the advantage that wavelength conversion independent from a polarization state of the signal light can be implemented by the aid of the cascade sum-frequency and difference-frequency all-optical wavelength converter and the conversion method.

A wavelength conversion filter, includes: a wavelength conversion layer in which a wavelength conversion material is dispersed in a transparent resin base material; and an ultraviolet absorption layer which is provided on the surface of the wavelength conversion layer and in which an ultraviolet absorber is dispersed in a transparent resin base material, wherein the wavelength conversion layer contains 0.01 to 30 parts by mass of the wavelength conversion material with respect to 100 parts by mass of the transparent resin base material included in the wavelength conversion layer.