32results about How to "Reduce far-field divergence" patented technology

The invention provides a long-distance sub-wavelength grating structure applied to an optical phased array transmitting unit. The structure comprises an upper-layer structure and a lower-layer structure which are arranged in an up-down stacked mode; the lower-layer structure is made of a material of which the refractive index is lower than that of the upper layer, such as various oxides; the upper-layer structure is a sub-wavelength grating structure made of materials such as silicon, silicon nitride, aluminum nitride, aluminum oxide and the like, and the refractive index of the materials is higher than that of the lower layer; the middle part of the upper-layer structure is a straight waveguide; sub-wavelength square blocks are arranged on two sides of the straight waveguide; and the sub-wavelength square blocks are arranged along the waveguide direction to form a grating. The long-distance sub-wavelength grating structure has the beneficial effects that the sub-wavelength grating waveguide is used for reducing the disturbance intensity of the grating to transmission light and increasing the effective length of the grating, so that the effective length of the grating is increased,and the far-field divergence angle of a light beam is reduced; the uniform emission of a near field can be controlled by controlling the position of the sub-wavelength square blocks; the structure issimple, the manufacturing difficulty is low, and the cost is low.

A semiconductor laser with high-power and high-beam-quality lasers. An external resonant cavity is built outside the semiconductor gain element, and a collimating optical element, a spectral dispersion element, and a coupling output mirror are sequentially arranged in the external resonant cavity. The semiconductor gain element consists of several active gain regions arranged in parallel in a straight line. One side of each active gain region is coated with a film layer with high reflectivity to the laser wavelength, and the other side is coated with a film layer with high transmittance to the laser wavelength. film layer. The collimating optical element is located behind the side of the semiconductor gain element coated with a high-transmittance film layer, and its central optical axis coincides with the central optical axis of the light beam emitted by the semiconductor optical gain element. The spectral dispersing element is placed at an angle behind the collimating optics. The outcoupling mirror is located behind the spectral dispersion element along the beam propagation direction. The invention improves the mode of laser oscillation and effectively increases the output power of the laser without affecting the quality of the laser beam.

The invention discloses a multi-overlaid layer tunnel cascaded semiconductor laser, which belongs to the field of semiconductor lasers. The multi-overlaid layer tunnel cascaded semiconductor laser comprises 2-4 single-layer laser units which are connected vertically, wherein two adjacent single-layer laser units are connected with each other by growing a tunnel junction unit layer with a special structure according to a semiconductor crystal growing rule; and a tunnel joint unit comprises a highly-doped PN junction and a super lattice layer which grows on the upper side or / and lower side of the PN junction regularly. The tunnel cascaded semiconductor laser is formed by a special tunnel junction with a super lattice, so that the output light power of the semiconductor laser is greatly increased, and the inner resistance and pressure drop at the tunnel junction in the semiconductor laser are lowered by using an optimized tunnel junction; an expansion waveguide is added into the semiconductor laser, so that a far-field divergence angle of light output is greatly reduced; and the multi-overlaid layer tunnel cascaded semiconductor laser has good economic benefit, and contributes to miniaturized application of a high-power semiconductor laser.

The invention provides an epitaxial structure of a laser. The epitaxial structure comprises a InP substrate, wherein a buffer layer, an N-type external limitation layer, an N-type internal limitation layer, a non-doping waveguide layer with graded refractive index, a quantum well active region, a non-doping waveguide layer with graded refractive index, a P-type internal limitation layer, a P-type external limitation layer, a corrosion blocking layer, a P-type wrapping layer, a P-type barrier gradually-changing layer, a P-type barrier abruptly-changing layer and a P-type ohmic contact layer are sequentially deposited on the InP substrate from bottom to top, wherein the pairs of quantum wells of the quantum well active region are not less than six, the quantum wells are of stress quantum well structures, wells are press stress, barriers are tension stress, the thickness of the barriers of the quantum well structures are not smaller than 10 nanometers, and the N-type internal limitation layer is a tension stress structural layer and employs a AlInAs material. By the laser, a far-field divergence angle of a semiconductor laser in a vertical direction can be reduced, and the coupling efficiency of the laser and an optical fiber is improved.

The invention provides a gallium stibino mid-infrared circular spot output low divergence angle edge photon emission crystal laser. The laser comprises an n type substrate, an n type electrode which is deposited on the reverse side of n type substrate, one-dimensional photonic crystals, a lower waveguide layer, an active layer, an upper waveguide layer, a p type cover layer, a ridge strip waveguide and a p type electrode, wherein the one-dimensional photonic crystals, the lower waveguide layer, the active layer, the upper waveguide layer, the p type cover layer, the ridge strip waveguide and the p type electrode are sequentially deposited on the front side of the n type substrate, and the ridge strip waveguide, the p type cover layer, the upper waveguide layer, the active layer, the lower waveguide layer, and the one-dimensional photonic crystals form a P-N knot. The alternating growth direction of the one-dimensional photonic crystals is perpendicular to the direction of the P-N knot, the direction of the ridge strip waveguide is parallel to the direction of the P-N knot, and the ridge strip waveguide and the one-dimensional photonic crystals form asymmetrical photonic crystal composite waveguides. The one-dimensional photonic crystals are imported to a ridge strip waveguide laser, and the mode perpendicular to the direction of the P-N knot can be regulated and controlled, so that the light field area of a ground mode is increased, and the far field divergence angle of the ground mode in the direction perpendicular to the P-N knot is reduced.

The invention discloses a resonant optical gyroscope based on a high-K fluoride resonant cavity. The resonant optical gyroscope comprises a laser, a beam splitter, phase modulators, ring-shaped resonators, a triangular prism, a fluoride wedge-shaped cavity, detectors, lock-in amplifiers, a PI circuit, an adder, a high-voltage amplifier, signal generators and an isolator; the PI circuit is used for modulating optical signals to enable physical quantities extracted from signals output from the detector A and B to be capable of reacting the rotation angle of a carrier, and the frequency of the emergent light of a light source and a modulating voltage of the phase modulators can be respectively changed according to the physical quantities, the feedback of an optical path can be realized, and the purpose that the optical paths propagating in the fluoride wedge-shaped cavity clockwise and anti-clockwise are resonant can be realized.

The invention discloses a semiconductor laser. The semiconductor laser comprises a lower-part flat plate waveguide and an upper-part ridge waveguide along a growth direction of an epitaxial layer anda ridge width unchanged region at a back side and a ride width narrowing region at a front side along an optical transmission direction, at the ridge width unchanged region, the ridge width of the upper-part ridge waveguide is maintained unchanged, at the ride width narrowing region, the ridge width of the upper-part ridge waveguide is gradually narrowed, the ridge width of a wide ridge end of theride width narrowing region is equal to the ridge width of the ridge width unchanged region, the ridge width of the ridge end of the ride width narrowing region is smaller than the ridge width of thewide ridge end, a narrow ride end is an optical output end, at the ridge width narrowing region, the equivalent refractive index of the upper-part ridge waveguide is gradually reduced with the ridgewidth gradually narrowed until the narrow ridge end approaches the equivalent refractive index of the lower-part flat plate waveguide, the longitudinal size and the transverse size of a base mode of the narrow ridge both are increased, so that the longitudinal scattering angle and the transverse scattering angle of output light both are reduced. The scattering angle of the output light of the semiconductor laser provided by the invention is smaller than the scattering angle of a conventional ridge waveguide-structure semiconductor laser.

The invention discloses a semiconductor laser and a manufacturing method thereof. The semiconductor laser integrates the first waveguide layer and the second waveguide layer in the passive area by butt-growing in a resonant cavity, and injects current into the active area to generate optical gain. When the lasing is output, it will pass through the double-layer waveguide in the passive area, so that when the light field is coupled to the lower waveguide and reaches the output end face, the vertical size of the spot is effectively increased, the near-field spot is expanded, and the far-field divergence angle is reduced. Therefore, the output quality of the light beam is improved, the adjustment of the light beam is beneficial, the coupling efficiency of the optical fiber is improved, and the coupling cost of packaging is reduced. At the same time, when the light field is transmitted from the double-layer waveguide in the passive area to the single-layer waveguide in the active area, the loss will increase compared with the use of only a single-layer waveguide, thereby increasing the loss of external feedback light, thereby improving the laser’s resistance. reflexes.

The invention provides a third-order distributed feedback terahertz quantum cascade laser structure and a making method thereof. The structure comprises a substrate, a ridge waveguide region and a third-order grating structure. The ridge waveguide region comprises a lower electrode, a sandwich region and an upper electrode in order from the bottom up. The sandwich region comprises a lower contact layer, an active region and an upper contact layer from the bottom up. The third-order grating structure comprises a plurality of parallel slits which are arranged in a periodic manner and pass through the upper electrode and the sandwich region in the vertical direction. The longitudinal duty ratio of the third-order grating structure is in the range from 8% to 15%. Terahertz wave is generated in the active region, is emitted from the slits by the mode selection effect of the third-order grating structure and is coupled in the space to the longitudinal ends of the ridge waveguide region. In the invention, the third-order grating is introduced in a waveguide structure of the terahertz quantum cascade laser and a relatively small far-field divergence angle is obtained by adjusting different grating duty ratios, thereby overcoming the problem that the third-order grating has a relatively big far-field divergence angle due to phase mismatch.

The invention discloses a red light semiconductor area array light source device for laser display. The red light semiconductor area array light source device for laser display comprises a VCSEL area array and a microlens array, wherein the VCSEL area array at least comprises a plurality of VCSEL units which are used for emitting circular laser beams, and the microlens array is formed by a plurality of microlens and used for performing collimation rounding on the laser beams output by the VCSEL area array and outputting the laser beams. The light source device can reduce optical elements in a projection display optical path, shorten the length of a lighting optical path, and improve the optical energy utilization rate. In addition, the VCSEL area array can reduce interference between VCSEL lasers and weaken laser speckles, and therefore projection display quality is improved. According to the red light semiconductor area array light source device, the area array light source packaging technology and VCSEL are adopted, a two-dimensional array is easy to integrate, and the defect that power transmitted by a single tube is poor can be overcome. The VCSEL is available in wafer test, reduces cost greatly and is easy in modularization and packaging.

A laser and a manufacturing method thereof, the laser comprising: a substrate and a double-ridge waveguide; wherein the double-ridge waveguide includes a lower-stage ridge waveguide and an upper-stage ridge waveguide; wherein the lower-stage ridge waveguide is formed on the substrate, It includes a spot enlargement layer, a first spacer layer, a grating layer, a second spacer layer, and an active layer from bottom to top; the upper mesa ridge waveguide is formed on the lower mesa ridge waveguide, and includes a cladding layer and a cover layer from bottom to top; The above-mentioned ridge waveguide includes two sections of wedge-shaped waveguides and one section of straight waveguides, and the two sections of wedge-shaped waveguides are respectively distributed at both ends of the straight waveguide. The invention realizes a high-power laser, improves the coupling efficiency between the laser and the optical fiber, and effectively reduces power consumption and cost.

The invention belongs to the technical field of semiconductor laser, and discloses a semiconductor laser spectrum beam combining device and method based on a collimation-deflection element. The devicecomprises a semiconductor laser array (1), and a fast axis collimating mirror (2), a light beam rotating element (3), a collimation-deflection element (4), a diffraction grating (5) and an output coupling mirror (6) which are sequentially arranged along a light path, wherein the collimation-deflection element (4) is used for refracting light beams emitted by different emission units and enablingthe light beams to enter the same area of the diffraction grating (5), and the diffraction grating (5) is used for diffracting a plurality of light beams overlapped in the same area at the same diffraction angle, so that the light beams become the same light beam and are outputted. Thus, by improving the composition of each component in the beam combining device, the arrangement mode and the internal structure of each component and the like, the problems of feedback of light beams emitted by an off-center emission unit, low beam combining efficiency and the like in the traditional semiconductor laser array spectrum beam combining mode can be effectively solved.

A semiconductor laser and a manufacturing method thereof, comprising the following steps: sequentially growing a buffer layer, a far-field reduction layer, a spacer layer, a quantum well material layer, and a grating layer on a substrate; and etching and removing the grating layer located in the mode spot converter region , make a grating from the grating layer in the laser area; grow a gap layer, an etching stop layer, a cladding layer and a contact layer in turn on the substrate with the grating; use the cladding layer and the contact layer to make an upper ridge waveguide, in which the laser area is The width of the upper ridge waveguide remains unchanged, and the width of the upper ridge waveguide in the mode spot converter area gradually decreases from the laser end to the light-emitting end of the device; after the etching stop layer other than the upper ridge waveguide is removed by selective wet etching, the etching stop layer is Lateral corrosion occurs under the upper ridge waveguide; the lower ridge waveguide is fabricated by etching from the gap layer of the mode spot converter region to the buffer layer. The mode-spot converter integrated on the semiconductor laser of the present invention can be realized by using a common contact photolithography process, which is beneficial to reduce the fabrication cost of the device.

The present invention discloses a ring micro-cavity laser with a directional output. The ring micro-cavity laser comprises an annular micro-cavity resonant cavity, and grating structures are etched and distributed on partial inner wall of the annular resonant cavity. The invention provides the annular semiconductor micro-cavity laser, the far field of output light is controlled through the grating structures distributed on the inner wall of a ring part, thus the small-angle single-direction output can be obtained by a high quality factor mode.