24 results about "Slope efficiency" patented technology

The invention relates to the technical field of aging test, and discloses a laser chip accelerated aging test method, which comprises the following steps: synchronously measuring the optical power, the threshold current, the slope efficiency and the emergent wavelength of a laser chip in an accelerated aging environment to obtain a time sequence data matrix; performing double sparse dictionary decomposition on the time series data matrix to obtain a normal feature coefficient and a degradation feature coefficient; calculating a target characteristic value of the time-varying covariance matrix based on the degradation characteristic coefficient, and generating a dynamic characteristic value sequence and a corresponding degradation stage identifier according to the target characteristic value; and based on the degradation stage identifier, inputting the dynamic characteristic value sequence into a life prediction model for life prediction, and obtaining the remaining service life. The method can accurately capture the nonlinear characteristic and the time evolution mode of the laser chip degradation process, automatically identify the time period characteristic which contributes to life prediction, and improve the service life of the laser chip. And the accelerated aging test accuracy of the laser chip is improved.

The application belongs to the technical field of laser materials, and relates to a holmium-praseodymium-scandium doped composite calcium fluoride single crystal as well as a preparation method and application thereof. 0.01 Pr x Sc y Ca 0.99‑x‑y F 2.01+x+y , wherein 0.005 <= x <= 0.015, 0.005 <= y <= 0.05; the crystal is obtained by growing the crystal in a vacuum environment through a temperature gradient method. Compared with the prior art, the application can realize high-efficiency laser output in a 2-3 mu m mid-infrared wave band, the grown crystal has the characteristics of high thermal conductivity, high chemical stability, high transmittance and high quality, and has the advantages of high gain bandwidth, high gain cross section, high power and high slope efficiency in the mid-infrared wave band, and has significant advantages in the fields of environmental monitoring, industrial processing, national defense and safety.

The application discloses a kind of to be related to the field of semiconductor laser, specifically discloses a kind of grating structure for DFB laser and its preparation method, DFB laser.The preparation method of grating structure includes: S1, grating layer is grown on initial epitaxial wafer;S2, grating layer is etched;S3, load into MOCVD reaction chamber, warm up to T1, keep warm first preset time;PH3 is continuously imported during the process of warming up;PH3 is imported flow rate F1 when keeping warm ends;S4, warm up to T2, PH3 and TMIn are continuously imported during the process of warming up;T2-T1>10 ℃, and PH3 import flow rate is increasing during the process of warming up;S5, cool down to T1, PH3 and TMIn are continuously imported during the process of cooling down;PH3 import flow rate is decreasing during the process of cooling down;S6, periodically repeat steps S4 and S5, until buried layer is obtained, grating structure is obtained.The application can reduce grating remelting, improve the crystal quality of grating structure, reduce interface roughness, so as to improve the side mode suppression ratio, slope efficiency of DFB laser.

According to the gallium nitride-based semiconductor laser with the gradually-changed polarized optical phonon energy waveguide layer, a fitting curve of In ion strength distribution or In atom concentration distribution of an upper waveguide layer and a lower waveguide layer is tested through SIMS, and a fitting curve of polarized optical phonon energy distribution meets any function distribution of Log3P1, Lop2P2 and Biphase. The spatial continuous regulation and control of the phonon energy of the optical field are realized, so that the LO phonon energy is continuously and gradually changed along the propagation direction, the phonon energy gradient is formed, the LO phonon scattering is improved, the inelastic scattering and energy relaxation of carriers and LO phonons are inhibited, the carrier transportation and phonon scattering are optimized, the service life of the carriers and the gain retention time are prolonged, and the optical field performance is improved. According to the invention, the threshold current density is reduced, the thermal stability of the laser is improved, the use power and the use temperature of the laser are improved, meanwhile, the phonon energy valley value is matched with the quantum well gain peak, the scattering loss is inhibited, additional scattering caused by phonon energy mutation is avoided, the light field limitation is enhanced, and the slope efficiency is improved.

The invention provides a gallium nitride-based semiconductor laser with a gradient radiation recombination coefficient waveguide layer, which is characterized in that a lower waveguide layer and an upper waveguide layer are respectively a gradient radiation recombination coefficient lower waveguide layer and a gradient radiation recombination coefficient upper waveguide layer; and a fitting curve of In ion strength distribution or In atom concentration distribution and a fitting curve of radiation recombination coefficient distribution of the waveguide layer on the gradient radiation recombination coefficient both meet any function distribution of GaussAmp, InvsPoly and Hill in an SIMS test. A fitting curve of In ion strength distribution or In atom concentration distribution and a fitting curve of radiation recombination coefficient distribution of the waveguide layer under the gradient radiation recombination coefficient both meet BiDoseResp function distribution in an SIMS test. According to the invention, carriers, quantum recombination and a light field are efficiently localized, the laser gain is improved, the carriers and the light field are efficiently localized in an active layer (quantum well), meanwhile, non-radiative recombination and absorption loss of a waveguide region are inhibited, and the threshold current, slope efficiency and reliability are further improved.

According to the gallium nitride-based semiconductor laser with the gradually-changed hole mobility waveguide layer, a fitting curve of In ion strength distribution or In atom concentration distribution, a fitting curve of valence band effective state density distribution and a fitting curve of hole mobility distribution of an upper waveguide layer and a lower waveguide layer which are tested by SIMS all meet any function distribution of ExpGrow1, ExpGrow2, Lorentz and Bradley; energy band degeneracy is improved, ionization impurities, polarization charges and energy band bending restriction are reduced, coupling of a heavy hole band and a light hole band with an SO band is regulated and controlled, valence band effective state density is improved, population inversion and laser gain are enhanced, hole mobility distribution of a waveguide layer is controlled to be in splayed distribution, interface scattering and ionization impurity scattering are inhibited, and the performance of the laser is improved. The hole mobility and the thermal stability are improved, the hole transport efficiency is enhanced, the hole leakage is reduced, and the slope efficiency, the optical power, the aging life and the temperature quenching ratio of the laser are improved.

The application provides a semiconductor laser element provided with a conductive phase change layer, and relates to the technical field of semiconductor photoelectric devices, and sequentially comprises a substrate, a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer and an upper limiting layer from bottom to top; the conductive phase change layer is arranged between the lower waveguide layer and the lower limiting layer and between the upper waveguide layer and the electron blocking layer; the conductive phase change layer has a reversible control phase change field; the phase change during the high-low temperature change in the epitaxial growth process is controlled; the phase change rate is improved from the minute order of magnitude to the picosecond order of magnitude; the resistivity and the carrier potential barrier are reduced; the single transverse mode lasing current and the threshold voltage are reduced; meanwhile, the conductive phase change layer also has a reversible control strain field; the uneven thermal stress distribution is improved; the In component fluctuation and segregation of the active layer are inhibited; the interface quality of the active layer is improved; the thermal stability and the optical catastrophe damage are inhibited; the confinement factor of the laser element is enhanced; and the lasing power and the slope efficiency of the laser element are improved.

The application relates to a Tm / Ho:YAG-SiO2 special optical fiber, a 2-micron single-frequency fiber laser based on the optical fiber and a preparation method, and belongs to the fiber laser field. The core of the special optical fiber is Tm / Ho:YAG, and the outer cladding is SiO2. The laser comprises a pump source, a fiber wavelength division multiplexer A and a laser resonant cavity arranged along an optical path. The pump source adopts a semiconductor LD. The laser resonant cavity is composed of a pair of fiber Bragg gratings, including a low-reflectivity Bragg grating and a high-reflectivity Bragg grating. The special optical fiber is arranged between the low-reflectivity Bragg grating and the high-reflectivity Bragg grating. The special optical fiber is prepared by a melting core method. The doping of Ho improves the absorption capacity of the gain optical fiber to the pump and the gain at the 2-micron waveband. The Tm / Ho:YAG-SiO2 special optical fiber is used to output a 2-micron waveband single-frequency fiber laser with higher output power and higher slope efficiency. 3+ ​

The application discloses a semiconductor green laser element, which comprises, from bottom to top, a substrate, a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer and an upper limiting layer in sequence, wherein the upper waveguide layer and the upper limiting layer are provided with a topological phonon transition layer, and the topological phonon transition layer comprises a first topological phonon transition layer, a second topological phonon transition layer and a third topological phonon transition layer. The application realizes the synergistic regulation of phonon transport, reduces the phonon scattering of the laser element, enhances the lattice thermal conductivity, improves the thermoelectric performance of the laser element, improves the heat dissipation performance of the laser element, reduces the heat accumulation of the active layer, reduces the temperature of the active layer, reduces the hole injection barrier and improves the hole injection efficiency, improves the overlap probability of the electron-hole wave function of the active layer, thereby strengthening the laser element, improving the aging light attenuation, the aging life and the reliability under the condition of high power and large current, and improving the lasing power and the slope efficiency of the laser element.

The application provides a semiconductor laser element provided with an ion conjugate layer, and relates to the technical field of semiconductor photoelectric devices, and sequentially comprises a substrate, a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper limiting layer from bottom to top; the ion conjugate layer is arranged between the active layer and the upper wave layer and between the active layer and the lower waveguide layer; the ion conjugate layer can improve the molar absorption coefficient and compensate the polarization field, induce local polarization, and then regulate the carrier and Fermi level, improve the small rabbit degeneracy of the laser element, reduce the absorption loss of the free carrier, promote the stimulated radiation to exceed the spontaneous radiation, improve the particle inversion of the non-equilibrium carrier in the resonant cavity of the laser element, reduce the lasing threshold, realize the room-temperature continuous oscillation, improve the slope efficiency of the laser element, reduce the valence band step of the active layer, improve the hole injection efficiency and injection uniformity, and improve the peak gain and gain uniformity of the laser element.

The application discloses a semiconductor laser element in the violet-ultraviolet wave band, which comprises, from bottom to top, a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer and an upper confinement layer, wherein the upper waveguide layer and the upper confinement layer are provided with an interlayer coherent hole tunneling layer, and the interlayer coherent hole tunneling layer comprises a first interlayer coherent hole tunneling layer, a second interlayer coherent hole tunneling layer and a third interlayer coherent hole tunneling layer. The application constructs a highly periodic electrostatic potential, tunes Feshbach molecular resonance to enhance the interaction between excitons and holes residing in different layers in the laser, reduces the Mg acceptor activation energy of the p-type semiconductor, improves the ionization efficiency of Mg, thereby inducing the interlayer coherent hole tunneling injection of the hole generation layer of the laser into the active layer, improving the hole injection efficiency of the active layer, improving the matching degree and uniformity of the electrons and holes in the active layer, and improving the optical power and slope efficiency of the laser element.

The application provides a semiconductor laser element provided with a triplet exciton enrichment layer, and relates to the technical field of semiconductor photoelectric devices, and sequentially comprises a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper confinement layer from bottom to top; the triplet exciton enrichment layer is arranged between the active layer and the upper wave layer and between the active layer and the lower waveguide layer; compared with the prior art, the triplet exciton enrichment layer is arranged between the active layer and the lower wave layer and between the lower confinement layer and the lower waveguide layer; in the laser element, the triplet exciton is enriched in the active layer through energy transfer, and is converted into a radiative monopole exciton through spin coupling inversion, so that the electron-hole wave function in the active layer realizes a radiative recombination efficiency close to 100%, the confinement factor is enhanced, continuous oscillation is realized, the excitation threshold of the laser element is reduced, and the optical power and the slope efficiency of the laser element are improved.

The application belongs to the technical field of semiconductor photoelectric devices, and particularly relates to a semiconductor laser element with a strain-induced exciton response layer, which comprises, from bottom to top, a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper confinement layer, wherein the upper waveguide layer and the electron blocking layer are provided with the strain-induced exciton response layer; the strain-induced exciton response layer is one of KV3Sb5, WSe2, ReO3, RbV3Sb5, CsV3Sb5 and KSbO3 or a combination of two or more thereof; the strain-induced exciton response layer is created by applying a local strain to the interface between the active layer and the upper waveguide layer and / or the lower waveguide layer, creating a strain field, changing the electron anisotropy, eliminating the sub-bandgap emission state of the spectrum overlap of the strain-induced exciton response layer, inhibiting the mode jump in the vertical direction, generating a single-mode laser, obtaining a good FFP far-field pattern, enhancing the exciton response of the active layer, reducing the driving voltage and excitation threshold of the laser element, enhancing the confinement factor, and improving the optical power and slope efficiency of the laser element.

The application provides a semiconductor laser, which comprises, from bottom to top, a substrate, a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper limiting layer; the active layer is a periodic structure composed of a well layer and a barrier layer; the refractive index coefficient of the well layer is greater than that of the barrier layer; the dielectric constant of the well layer is greater than that of the barrier layer; and the piezoelectric polarization coefficient of the well layer is greater than that of the barrier layer. The application differentiates the refractive index coefficient, the dielectric constant and the piezoelectric polarization coefficient of the well layer and the barrier layer in the active layer, thereby improving the photon degeneracy, making the stimulated radiation of the laser greater than the spontaneous radiation, improving the coherence, the limiting factor and the slope efficiency of the transverse mode, reducing the number of longitudinal modes and the mode variation, improving the time coherence of the longitudinal mode and the far field FFP image quality, the beam quality factor and the focusing spot resolution.

The application discloses a laser element containing a spin helical inductor layer, which comprises, from bottom to top, a substrate, a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper limiting layer; the active layer is adjacent to the lower waveguide layer, or a first spin helical inductor layer is arranged between the active layer and the lower waveguide layer; the active layer is adjacent to the upper waveguide layer, or a second spin helical inductor layer is arranged between the active layer and the upper waveguide layer; the first spin helical inductor layer and the second spin helical inductor layer are both three-dimensional topological core-shell structures. According to the application, the hole injection barrier is reduced, the hole injection efficiency is enhanced, meanwhile, the electron injection barrier of the active layer is improved, the electron overflow is reduced, the radiation recombination efficiency of the electron-hole wave function in the active layer is improved, the laser limiting factor is improved, the internal loss is reduced, and the laser emission power and the slope efficiency are improved.

The application provides a semiconductor laser with a thermoelectric optimal value control layer, which comprises, from bottom to top, a substrate, a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper limiting layer, and a thermoelectric optimal value control layer is arranged between the substrate and the lower limiting layer; the Si doping concentration of the thermoelectric optimal value control layer is greater than the Si doping concentration of the substrate and the lower limiting layer, the C impurity concentration of the thermoelectric optimal value control layer is less than the C impurity concentration of the lower limiting layer, and the H impurity concentration of the thermoelectric optimal value control layer is less than or equal to the H impurity concentration of the lower limiting layer. The application improves the mode gain, power factor and slope efficiency of the laser system, and the slope efficiency is improved by 125%, the optical power is improved by 37%, and the limiting factor is improved by 50%.

The application provides a semiconductor laser element with an interlayer hot exciton conversion layer, and relates to the technical field of semiconductor optoelectronic devices, which comprises, from bottom to top, a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer, and an upper confinement layer; an interlayer hot exciton conversion layer is arranged between the upper confinement layer and the electron blocking layer and between the lower confinement layer and the lower waveguide layer; in the charge transport process of the laser element, the interlayer hot exciton conversion layer forms a mismatched momentum, generates a large number of interlayer hot excitons, and is converted into a tightly bound interlayer exciton after the release of extra energy, thereby improving the peak gain of the active layer of the laser element and improving thermal degradation, reducing non-radiative recombination centers, improving the refractive index dispersion of the laser element, improving the confinement factor of the laser element, improving the mode gain, improving the radiation recombination efficiency of the active layer of the laser element, reducing the excitation threshold of the laser element, and improving the optical power and the slope efficiency of the laser element.

The invention discloses a short-wave infrared InP-based photonic crystal surface emitting laser, and relates to the technical field of lasers. The laser comprises an n-type InP substrate, an n-type coating layer, a multi-quantum well layer, an electron blocking layer, a photonic crystal layer, a p-type coating layer and a metal distributed Bragg reflection layer which are sequentially arranged in the stacking direction. The photonic crystal layer is formed by periodically arranging a plurality of tri-lattice units, and a surrounding distributed Bragg reflection structure is arranged around the photonic crystal layer; at least two lattice points in the tri-lattice unit have lateral and longitudinal offsets with respect to another lattice point. Planar light leakage is suppressed through the peripheral distributed Bragg reflection structure, and in combination with active regulation and control of tri-lattice micro-offset on planar coupling and vertical radiation proportion, and through the synergistic effect of the planar coupling and the vertical radiation proportion, the simulation result shows that the slope efficiency is improved to 0.18 W / A and the vertical radiation loss proportion is improved to 45% while low threshold gain (26cm <-1 >) is kept, and the performance of the device is improved. Unification of low threshold and high efficiency is achieved, and the method is suitable for the fields of optical communication, laser radar and the like.

The invention discloses a polarization and chirality adjustable all-solid-state vector vortex laser and application. The all-solid-state vector vortex laser comprises a pumping source, a laser crystal and an optical resonant cavity, the optical resonant cavity is provided with a resonant light path, the pumping source is arranged outside the optical resonant cavity and provides pumping light for the laser crystal, and the laser crystal is arranged on the resonant light path, absorbs the pumping light and generates stimulated radiation light; and a vortex wave plate is also arranged in the optical resonant cavity and is also arranged on the resonant optical path. The output laser of the all-solid-state vector vortex laser has the excellent characteristics of high polarization purity, high power output, high slope efficiency, high light beam quality and the like, the polarization state and the space phase state can be controlled at the same time only based on the vortex wave plate, the vector vortex laser with high conversion efficiency can be provided through the stable configuration, and the all-solid-state vector vortex laser can be used for controlling the polarization state and the space phase state at the same time. The method is suitable for multiple fields, and has wide application prospects and remarkable technical advantages.

Aspects of the present disclosure provide techniques for performing a safety test of a laser diode associated with an ophthalmic surgical apparatus. An example method determining a measured slope efficiency of the laser diode based on a plurality of different current levels applied to an input of the laser diode and a plurality of different output power levels associated with the laser diode, determining an expected slope efficiency of the laser diode based on a measured operating temperature of the ophthalmic surgical apparatus, determining a result of the safety test of the laser diode based on the measured slope efficiency of the laser diode and the expected slope efficiency for the laser diode, and outputting an electrical signal indicating a result of the safety test of the laser diode.

The invention provides a preparation method of a deuterium-doped and carrier gas synergistic anti-radiation optical fiber, the optical fiber and application, and belongs to the technical field of anti-radiation optical fibers, the preparation method comprises the following steps: firstly, preparing an optical fiber preform with a fiber core doped with rare earth ions and OD groups by adopting an improved chemical vapor deposition and solution doping combined technology; drawing the optical fiber preform to prepare a double-cladding rare earth ion doped optical fiber; and finally carrying out carrier gas treatment on the double-clad rare earth ion doped optical fiber, the carrier gas being at least one of deuterium gas, hydrogen gas or oxygen gas, and obtaining the anti-radiation optical fiber. Through the synergistic effect of introduced OD groups and loaded gas molecules, the anti-radiation stability of the prepared anti-radiation optical fiber is jointly enhanced, after the finally prepared anti-radiation optical fiber is irradiated by gamma rays with the total dose of 200Gy (Si), the laser slope efficiency change at the 1080nm wave band is less than 5%, the radiation darkening effect is thoroughly inhibited, and the anti-radiation stability of the prepared anti-radiation optical fiber is improved. The problem that in the prior art, the anti-radiation performance is insufficient or cannot be maintained for a long time is solved.

The application relates to the technical field of semiconductor devices, in particular to a semiconductor laser element with a strain polarity topological layer. The laser element has strain polarity topological layers between the upper confining layer and the upper waveguide layer and between the lower confining layer and the lower waveguide layer; the layer is a three-dimensional high-order topological superlattice structure formed by one or more of SrZnSO, PbTiO3, Ta2PdS5, CdPS3, SrTiO3 and hBN; the strain polarity topological layer generates polarity anti-vortex and polarity topological characteristics, reduces the polarization effect of the active layer, improves the uniformity of carrier injection, enhances tunable second harmonic and nonlinear optical properties, makes the laser propagate along the direction of the active layer, prevents light leakage to the substrate, suppresses the substrate mode, improves the far-field image quality, more limits the internal light field between the upper waveguide layer and the lower waveguide layer, reduces optical loss, improves the mode gain of the laser, enhances the confinement factor and gain uniformity, reduces the excitation threshold of the laser element, and improves the optical power and slope efficiency of the laser element.

This invention proposes a gallium nitride-based semiconductor laser with a hole-burning suppression layer, comprising, from bottom to top, a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer, and an upper confinement layer. This invention sets the distribution and variation trend of Al or In element concentrations in the hole-burning suppression layer, the upper confinement layer, the upper waveguide layer, and the lower waveguide layer, thereby controlling the uniformity of interface strain, the uniformity of interface Al element concentration distribution, and the interface quality of the laser structure. This improves the quantization of injected carrier energy, increases the carrier utilization rate in the injected active region, reduces the coupling time constant between electrons and photons in the active layer, reduces the number of interface states, and reduces the standing wave reduction caused by stimulated emission and the interaction between defects and interface states, as well as the population inversion distribution of standing wave interference particles excited by the laser resonator. This suppresses abrupt drops in the gain curve at any frequency position, suppresses the hole-burning effect, and improves slope efficiency.

The invention discloses a high-power 980nm-band single-frequency fiber core pumping fiber laser, and belongs to the field of optics. The invention aims to solve the problems of low output power and low amplification efficiency of the existing 980nm-band single-frequency laser. The optical fiber laser comprises a single-frequency seed source and at least one optical fiber amplification stage which is arranged in series, each optical fiber amplification stage adopts a high-ytterbium-doped gain optical fiber of fiber core pumping, and a narrow-band filtering assembly is arranged at the output end of the gain optical fiber so as to restrain amplified spontaneous radiation generated in the amplification process. By adopting a fiber core pumping mode and combining with a highly ytterbium-doped and short-length gain fiber, on the premise of keeping single-frequency operation, high-power and high-efficiency laser output of a 980nm wave band is realized, and meanwhile, the stability of a system in a high-power single-frequency working state is favorably improved. In a preferable embodiment, single-frequency laser output not lower than 30 W can be achieved, the slope efficiency of at least one optical fiber amplification stage is not lower than 60%, and the all-fiber laser has the advantages of being simple in structure, all-fiber and high in reliability.