13results about How to "Improve slope efficiency" patented technology

The invention relates to the technical field of lasers, and discloses a multi-junction vertical cavity surface emitting laser and a preparation method thereof. The laser comprises a substrate layer, an epitaxial structure, a first oxide layer and a second oxide layer, wherein the epitaxial structure comprises a first reflector layer, an active layer comprising a plurality of barrier layers and tunnel junctions, and a second reflector layer; the first oxidation layer with a first oxidation hole is arranged on one side of the tunnel junction, the second oxidation layer is arranged on the other side of the tunnel junction and is provided with a second oxidation hole concentric with the first oxidation hole, and the oxidation depth of the first oxidation layer is larger than that of the second oxidation layer; and one tunnel junction, the first oxide layer and the second oxide layer form an integrated structure which is arranged in one trough of the standing wave field. An optical field limiting structure in which oxide layers with long upper parts and short lower parts are arranged on two sides of a tunnel junction is formed, so that more high-order optical modes in the resonant cavity are ensured, transverse current can be effectively limited, increasing of series resistance and shortening of the effective cavity length of a standing wave field can be avoided, and the photoelectric conversion efficiency is further improved.

The utility model relates to the technical field of semiconductor photoelectric devices, in particular to a semiconductor laser chip, which comprises a substrate and an epitaxial layer, the section of the epitaxial layer along the laser emitting direction is a first end face, the section of the epitaxial layer opposite to the laser emitting direction is a second end face, the first end face is provided with an antireflection film layer, and the second end face is provided with a second antireflection film layer. The second end face is provided with a high-reflection film layer, and the reflectivity of the antireflection film layer is smaller than that of the high-reflection film layer; the refractive index of the epitaxial layer is greater than or equal to that of the antireflection film layer; the refractive index of the epitaxial layer is larger than or equal to that of the high-reflection film layer. According to the utility model, by designing the refractive index and the reflectivity of the antireflection film layer and the high-reflection film layer, the laser modulus of the optical waveguide layer is reduced, stimulated radiation is accelerated to exceed spontaneous radiation, the threshold current density of the laser is reduced, and the slope efficiency is improved; meanwhile, light field distribution of the optical waveguide is optimized, and light absorption loss and waveguide loss are reduced.

The invention discloses a red light Vcsel structure and a manufacturing method thereof. The red light Vcsel structure comprises a substrate, a buffer layer, an N-type DBR reflecting layer, a resonant cavity layer and a P-type DBR reflecting layer. The resonant cavity layer comprises an Al < 0.5 > In < 0.5 > P lower limiting layer, a lower waveguide layer, a multi-quantum well layer, an upper waveguide layer, an electron blocking layer and an Al < 0.5 > In < 0.5 > P upper limiting layer which are sequentially stacked from bottom to top; the resonant cavity layer meets nL = m lambda / 2, n is the average refractive index of the resonant cavity layer, L is the length of the resonant cavity layer, lambda is the resonant wavelength, and m is 3; the thickness of the Al0. 5In0. 5P lower limiting layer is more than three times thicker than that of a conventional short cavity length structure with m being 1, and overflow of carriers can be effectively limited; the electron blocking layer is composed of a superlattice structure formed by alternately growing a plurality of groups of Al0. 5In0. 5P layers and tensile stress (Al1-x2Gax2) y2In1-y2P layers, 0.05 < = x2 < = 0.1, y2 > 0.52, an obvious bandwidth difference is formed, overflow of current carriers is effectively blocked, y2 is gradually increased from the lower layer to the upper layer, and high-quality growth of the epitaxial layer is ensured while the electron blocking effect is achieved.

The invention relates to the technical field of semiconductor photoelectric devices, and particularly discloses a gallium nitride-based semiconductor laser element with a carrier concentration matching layer. The gallium nitride-based semiconductor laser element with the carrier concentration matching layer sequentially comprises a substrate, a lower coating layer, a lower waveguide layer, an active layer, an upper waveguide layer and an upper coating layer from bottom to top, and the carrier concentration matching layer is arranged between the upper waveguide layer and the upper coating layer; according to the gallium nitride-based semiconductor laser element with the carrier concentration matching layer, by regulating and controlling the peak electron drift rate interface steep degree and the transverse sound velocity interface steep degree of the interface between the carrier concentration matching layer and the active layer and the interface between the carrier concentration matching layer and the upper coating layer, the valence band order of the laser is reduced, and the hole injection efficiency and the hole transport efficiency are improved; and the carrier injection uniformity and the laser gain uniformity are improved, so that the slope efficiency, the optical power and the photoelectric conversion efficiency of the laser are improved, the power consumption is reduced, and the service life is prolonged.

This invention discloses an end-face coated crystal optical element for a laser resonator and its fabrication method, belonging to the field of optical element fabrication. It includes an optical crystal, a high-reflectivity film disposed on one end face of the optical crystal, and a partially transmissive film disposed on the other end face. The high-reflectivity film sequentially includes Y-coatings along the end face of the optical crystal outwards. b F3 First Floor, H f O2 first layer, Y b F3 Second Layer, H f O2 second layer...Y b F3, Q layer, H f O2, Q layer. This invention utilizes Y... b 3+ Sensitization improves pump absorption efficiency and through Y b To E r Energy transfer effectively alleviates high-doped E r The self-termination effect in YAG lasers enables high efficiency and high energy output of 2940nm lasers, making them suitable for fields such as medical aesthetics and precision machining.

The invention relates to a method for preparing a VCSEL device, in particular to a method for preparing a VCSEL device with a non-oxidized tunnel junction series multi-quantum well structure, which solves the technical problems of low optical power density and electro-optical efficiency, large light output aperture, low modulation rate, inability to be integrated at high density and low brightness in VCSEL devices prepared by the prior art. The invention provides a method for preparing a VCSEL device with a non-oxidized tunnel junction series multi-quantum well structure, comprising the steps of epitaxially growing an N-type DBR structure, epitaxially growing a first quantum well and a first phase adjustment layer to form a first intermediate terrace, preparing a first ion implantation layer, epitaxially growing a first tunnel junction, epitaxially growing a second quantum well, a second phase adjustment layer, a second intermediate platform, a second ion implantation layer and a second tunnel junction, epitaxially growing a third quantum well, a third phase adjustment layer, a third intermediate platform and a third ion implantation layer, epitaxially growing a P-type DBR structure, preparing an ohmic contact electrode and performing wafer cleavage.

The invention discloses a semiconductor laser with a lower waveguide layer for suppressing heat fading, which sequentially comprises a substrate, a lower coating layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper coating layer from bottom to top, the waveguide layer under the low oscillation threshold is any one or any combination of an InGaN / GaN superlattice, an InGaN / AlGaN superlattice, an InGaN / AlInGaN superlattice, an InGaN / AlInN superlattice, a GaN / AlGaN superlattice, a GaN / AlInGaN superlattice and a GaN / AlN superlattice, and the thickness of the waveguide layer under the low oscillation threshold is 5-1000 nm. The waveguide side wall scattering loss and quantum well absorption loss of the laser are reduced, the internal light absorption loss of the laser is reduced, heat fading caused by non-radiative recombination is inhibited, the threshold current of the laser is reduced, and the slope efficiency is improved.

The semiconductor laser chip comprises a substrate and an epitaxial layer, the epitaxial layer is arranged on the upper layer of the substrate, the surface of a first cavity surface of the epitaxial layer is plated with an antireflection layer, and the surface of a second cavity surface of the epitaxial layer is plated with a high reflection layer. The antireflection layer comprises a first sub-antireflection layer, a plurality of second sub-antireflection layers and a plurality of third sub-antireflection layers which are sequentially plated on the surface of the first cavity surface, and the plurality of second sub-antireflection layers and the plurality of third sub-antireflection layers are sequentially and alternately arranged to form a periodic structure; the electric field intensity of simulation light field distribution of the antireflection layer is in periodic oscillation distribution, and the peak electric field intensity from the first sub antireflection layer to the second sub antireflection layer or the third sub antireflection layer on the outermost layer in the laser emitting direction is in a decreasing trend. Light field distribution of the laser can be regulated and controlled, light field limitation is enhanced, stimulated radiation is accelerated to exceed spontaneous radiation, threshold current density of the laser is reduced, and slope efficiency is improved.

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 invention discloses a gallium nitride-based semiconductor laser chip with a low-oscillation-threshold lower waveguide layer, which sequentially comprises a substrate, a lower coating layer, a lower waveguide layer, an active layer, an upper waveguide layer and an upper coating layer from bottom to top, and is characterized in that the lower waveguide layer is the low-oscillation-threshold lower waveguide layer; the waveguide layer under the low oscillation threshold is any one or any combination of InGaN, GaN, InN and AlInGaN; and the deformation potential distribution of the waveguide layer under the low oscillation threshold value has broken line type distribution. According to the invention, the deformation potential of the lower waveguide layer and the active layer of the laser is regulated and controlled, the carrier delocalization of the active layer and the lower waveguide layer is reduced, the electron hole injection and transport uniformity is improved, the population inversion is accelerated, and the threshold current density is reduced.

The invention provides a gallium nitride-based semiconductor laser with a hole burning inhibition layer. The gallium nitride-based semiconductor laser 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 which are sequentially arranged from bottom to top. The distribution state and change trend of Al element concentration or In element concentration in the hole burning suppression layer, the upper limiting layer, the upper waveguide layer and the lower waveguide layer are set, the interface strain uniformity, the interface Al element concentration distribution uniformity and the interface quality of the laser structure are regulated and controlled, quantization of injected carrier energy is improved, and the performance of the laser structure is improved. The utilization rate of carriers injected into an active area is improved, the coupling time constant of electrons and photons in an active layer is reduced, the number of interface states is reduced, standing wave reduction caused by stimulated radiation and defect and interface state interaction and standing wave interference population inversion distribution excited by a laser resonant cavity are reduced, and the stability of the laser is improved. Therefore, sudden decrease of any frequency position of the gain curve is suppressed, the hole burning effect is suppressed, and the slope efficiency is improved.

The present invention discloses a red light Vcsel structure and a manufacturing method thereof. The red light Vcsel structure comprises a substrate, a buffer layer, an N-type DBR reflective layer, a resonant cavity layer and a P-type DBR reflective layer; the resonant cavity layer comprises Al 0.5 In 0.5 P lower confinement layer, lower waveguide layer, multi-quantum well layer, upper waveguide layer, electron blocking layer, Al 0.5 In 0.5 The confinement layer on P; the resonant cavity layer satisfies: nL=mλ / 2, where n is the average refractive index of the resonant cavity layer, L is the length of the resonant cavity layer, λ is the resonant wavelength, and m is 3; so that Al 0.5 In 0.5 The thickness of the P lower confinement layer is more than 3 times thicker than that of the conventional short cavity length structure with m=1, which can effectively limit the overflow of carriers; the electron blocking layer is composed of multiple groups of Al 0.5 In 0.5 P layer and tensile stress (Al 1‑x2 Ga x2 ) y2 In 1‑y2 The superlattice structure consists of alternating P layers, where 0.05≤x2≤0.1 and y2>0.52, forming an obvious bandwidth difference, effectively blocking the overflow of carriers, and y2 gradually increases from the lower layer to the upper layer, achieving the electron blocking effect while ensuring the high-quality growth of the epitaxial layer.

The utility model discloses a nitride semiconductor laser, which comprises a heat dissipation heat sink and a laser structure, and is characterized in that the laser structure comprises a first type waveguide layer, a quantum well layer and a second type waveguide layer which are stacked in sequence; wherein the first type is a P type, and the second type is an N type; or, the first type is an N type, and the second type is a P type; the doping concentration of the P-type waveguide layer is gradually changed along the growth direction of the device; the nitride semiconductor laser is obtained by growing and stripping on the gallium surface of the gallium nitride substrate. The gallium-based solar cell is obtained by growing and stripping on a gallium surface, thereby being beneficial to heat scattering and improving the high-power output performance of the device; and meanwhile, in cooperation with gradient doping of the P-type waveguide layer, penetration dislocation can be reduced through staged lattice matching.