10 results about "Lasing threshold" patented technology

The invention relates to the technical field of manufacturing of deep ultraviolet semiconductor laser devices, in particular to a transverse-structure deep ultraviolet laser capable of promoting carrier injection and a preparation method of the transverse-structure deep ultraviolet laser. Comprising a substrate, a template layer, an n-type AlGaN contact layer, an n-AlN thin layer, an n-type AlGaN surrounding layer, a lower waveguide layer, a multi-quantum well layer, an upper waveguide layer, a p-type AlGaN surrounding layer, a p-type contact layer and a p-type metal electrode layer which are sequentially stacked from bottom to top. The surface of one side, far away from the template layer, of the n-type AlGaN contact layer is of a step-shaped structure; the step-shaped structure comprises a ridge surface and an independent step surface, the ridge surface bears the n-AlN thin layer, and the step surface is independently provided with an n-type metal electrode layer. The invention has the advantages that: heterojunction with different Al components is introduced into the n-type region and the p-type region of the device to generate two-dimensional electron gas, so that better electron injection and hole injection are realized, electron transmission paths are reduced, the joule heat of the device is reduced, the lasing threshold is greatly reduced, and the luminous power is improved.

A method of controlling an optical output power of a laser diode associated with a photodiode includes obtaining first optical trimming parameters indicative of a first optical output power of the laser diode at a first laser diode current and a second optical output power of the laser diode at a second laser diode current above lasing threshold. Next, second electrical trimming parameters indicative of a photodiode characteristic curve of photodiode current versus laser diode current are obtained. A first photodiode current and a second photodiode current at a laser diode currents below lasing threshold. A slope of a photodiode current versus laser diode current is determined. The optical output power of the laser diode above lasing threshold is controlled based on the first optical trimming parameters, the second electrical trimming parameters and the slope of the photodiode current versus laser diode current below lasing threshold.

The invention discloses a wavelength-adjustable Tamm laser based on a two-dimensional perovskite material and a preparation method thereof, the laser sequentially comprises a substrate, a DBR reflecting layer formed by alternating titanium dioxide and silicon dioxide, a two-dimensional perovskite absorbing layer and a silver reflecting layer from bottom to top, the bottom silicon dioxide layer is in contact with the substrate, and the bottom silicon dioxide layer is in contact with the silver reflecting layer. The top titanium dioxide layer is in contact with the two-dimensional perovskite absorption layer, and the thickness of the top titanium dioxide layer is smaller than that of the other titanium dioxide layers; the silver reflecting layer and the DBR reflecting layer form a Tamm state, and the high exciton binding energy of the two-dimensional perovskite material and the optical Tamm state form a strong coupling effect. The DBR structure introduced by the laser has high reflectivity for a target optical wave band, light is limited in the perovskite layer, and the Tamm state promotes the enhancement of the optical field intensity near the perovskite layer, so that the lasing and reduction of the thickness of top titanium dioxide are realized, the phase round-trip condition is met, and the maximization of the enhancement of an electric field in the perovskite layer is realized; and a low laser threshold is realized.

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.

A laser system may include a controller configured to direct a plurality of temporally spaced-apart electrical pulses to a device that optically pumps a lasing medium, and a lasing medium configured to output a quasi-continuous laser pulse in response to the optical pumping. The plurality of temporally spaced-apart electrical pulses may include (a) a first electrical pulse configured to excite the lasing medium to an energy level below a lasing threshold of the lasing medium, and (b) multiple second electrical pulses following the first electrical pulse. The quasi-continuous laser pulse is output in response to the multiple second electrical pulses.

The present application relates to the technical fields of deep ultraviolet semiconductor laser device manufacturing, and particularly relates to a kind of promoting carrier injection's lateral structure deep ultraviolet laser and preparation method thereof.Deep ultraviolet laser includes substrate, template layer, n-type AlGaN contact layer, n-AlN thin layer, n-type AlGaN surrounding layer, lower waveguide layer, multiple quantum well layer, upper waveguide layer, p-type AlGaN surrounding layer, p-type contact layer and p-type metal electrode layer, which are stacked from bottom to top.The side surface of n-type AlGaN contact layer away from template layer is in stepped structure.The stepped structure includes ridge surface and independent step surface, the ridge surface bears n-AlN thin layer, and the step surface separately sets n-type metal electrode layer.The advantages are that two-dimensional electron gas is generated by introducing heterojunction with different Al components in n-type region and p-type region of the device, better electron injection and hole injection are achieved, electron transmission path is reduced, device joule heat is reduced, lasing threshold is greatly reduced, and light emitting power is improved.

An edge-emitting diode-laser bar comprises a plurality of diode-laser junctions. The diode-laser junctions are vertically arranged and separated by tunneling junctions. Each diode-laser junction is overlaid by a current confinement layer. Together, these current confinement layers laterally constrain current flow through emitters in this semiconductor structure. Active regions in vertically-aligned emitters have the same current density. Vertically-aligned emitters have the same threshold current for lasing and the same optical output power. A plurality of such diode-laser bars is assembled into a high-output-power high-brightness vertical stack.

The application discloses a gallium nitride-based semiconductor laser element, 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, and a polariton lattice layer is arranged between the upper waveguide layer and the upper confinement layer. The polariton lattice layer has a broken space inversion symmetry, forms a three-dimensional topological monopole, controls anisotropic polariton propagation, embeds a vector between an electron hole containing band on a Fermi surface, improves a motion rate of the polariton, induces asymmetric barriers at the top and the bottom of the active layer, improves a tunneling probability of a carrier, enhances a laser confinement factor and optical power, reduces dynamic conductivity caused by band transition, improves transport and injection uniformity of a hole in the active layer, suppresses generation of a non-radiative charged exciton and Auger recombination of an exciton-charge, enhances cascade conversion and spin-orbit coupling between energy bands, reduces a lasing threshold by increasing a high-energy level exciton occupation number inversion.

The utility model belongs to the technical field of light field modulation, and particularly relates to a Fabry-Perot microcavity laser based on a low-light-level element and a light field test system. According to the Fabry-Perot micro-cavity laser, two high-reflection plane mirrors are arranged in parallel, a laser gain medium is arranged in the middle of each high-reflection plane mirror, four corners of each high-reflection plane mirror are supported by spacers to form a laser resonant cavity, and a low-light-level element is prepared on the surface of one plane mirror. A Fabry-Perot microcavity laser is used in a common light field test system to form the light field test system, and can be used for light field test and modulation: monitoring an output laser pattern and a laser spectrum, and adjusting the position of the laser to obtain a lasing threshold curve of a microcavity; according to the utility model, through designing the matching relation between the optical continuous interface or diffraction structure configuration and the micro-cavity configuration in the micro-cavity laser, the modulation of the optical field in the cavity can be realized, so that the customized output of the optical field of the high-quality factor micro-cavity laser and the specific laser mode can be realized.

The present disclosure provides a topologically protected semiconductor laser array with supersymmetry matching, and relates to the technical field of semiconductor lasers. The topologically protected semiconductor laser array with supersymmetry matching comprises a topological main array for generating an output light beam by pumping, and a supersymmetry counterpart array coupled with the topological main array; wherein the coupling distance between the topological main array and the supersymmetry counterpart array is regulated, so that high-order modes in the light beam are coupled from the topological main array to the supersymmetry counterpart array through an evanescent wave coupling mechanism, and the lasing threshold of the high-order modes is regulated.