21results about How to "Increase modulation bandwidth" patented technology

The invention belongs to the technical field of optical communication chips, and particularly relates to an HEMT (High Electron Mobility Transistor)-driven near ultraviolet bidirectional optical communication monolithic integrated chip with the wavelength of 365 nm and a preparation method thereof. Functions of an optical transmitter, an optical receiver and a driver are integrated into one chip, light emitted by a transmitting end is coupled into an optical waveguide and is detected by a photoelectric detector, an optical signal is converted into an electric signal, information transmission in the chip is completed, and a bidirectional optical communication link can be constructed without two sets of optical transmitters and optical receivers; the DBR Bragg reflection layer is adopted to reflect emergent light in all directions back to the waveguide of the straight waveguide area, so that the emergent light is transmitted to a receiving end along the waveguide of the straight waveguide area, by designing the material and period of the DBR, about 70% of the emergent light can be reflected, and the detection accuracy is improved; the integrated HEMT drive reduces the size and complexity of the whole circuit, the HEMT can still keep good linear performance under high current, distortion is reduced, and the stability of LED light output is ensured.

The invention relates to the field of communication, and provides a visible light communication method for a display and MIMO system, and the method comprises the steps: obtaining to-be-displayed content and to-be-transmitted data; according to the number S of pixels, needing to be lightened at a single time, of the to-be-displayed content, the QAM order of a channel corresponding to each pixel is determined; dividing the data to be transmitted into P groups of transmission data, so that each group of transmission data is transmitted through one channel; respectively performing QAM mapping on the P groups of transmission data according to the QAM order to generate P groups of QAM code elements; respectively carrying out OFDM modulation on the P groups of QAM code elements to generate P modulation signals; and driving the micro-LED array to synchronously transmit P paths of optical signals and perform communication based on the P modulation signals. According to the invention, the advantages of MIMO and micro-LED are combined, the spectrum utilization efficiency is improved on the basis of improving the modulation bandwidth, and the communication rate of a visible light communication system can be maximized.

The invention provides a high-speed VCSEL chip and a manufacturing method, and belongs to the technical field of semiconductors, the high-speed VCSEL chip comprises a GaAs substrate, and the GaAs substrate is sequentially provided with an n-DBR, a quantum well active region, a p-DBR, a p-In < 0.49 > Ga < 0.51 > P inner cavity contact layer and a u-DBR; according to the invention, the number of pairs of series connection of the p-DBR is reduced, and the series resistance of the chip is reduced, so that the resistance of the chip is still kept at a reasonable level when the chip with a small oxidation aperture is manufactured, and the reliability and the high-temperature performance of the chip are better; the band gap width of the p-In0. 49Ga0. 51P inner cavity contact layer is 1.88 eV which is much larger than 1.42 V of GaAs, and the negative effect of light absorption in the 850 nm wave band is removed. A u-DBR table top is reserved at a light outlet, so that a large threshold gain difference exists between a fundamental mode and a high-order mode. In addition, the thick p-In0. 49Ga0. 51P inner cavity contact layer still has certain light field intensity, so that the loss of a high-order mode is further increased, the chip can stably work in a fundamental mode, and the modulation bandwidth is greatly increased.

This invention relates to a differential modulator based on a double-layer lithium niobate waveguide and its fabrication method, belonging to the field of optical communication technology. It includes an optical structure and an electrical structure; the optical structure includes a beam splitter, a first lithium niobate modulation waveguide, a second lithium niobate modulation waveguide, and a beam combiner; wherein the output end of the beam splitter is connected to the input ends of the two lithium niobate modulation waveguides, and the input end of the beam combiner is connected to the output ends of the two lithium niobate modulation waveguides; the crystal axes Z-directions of the first and second lithium niobate modulation waveguides are opposite; the electrical structure includes GSSG differential electrodes and on-chip terminating resistors; wherein the differential electrodes are sequentially arranged with a first ground electrode, a first signal electrode, a second signal electrode, and a second ground electrode; both the first and second lithium niobate modulation waveguides are disposed between the first and second signal electrodes. This invention improves modulation efficiency and enhances device stability and modulation bandwidth.

The invention discloses a reflection mode fluorescence conversion white light source for communication and illumination, and belongs to the field of visible light communication and solid-state illumination. The divergence angle, the modulation bandwidth, the color rendering index, the angle color uniformity and the thermal stability of the white light source are remarkably improved, and the overall performance of a visible light communication and solid-state lighting system is enhanced. The specific implementation method comprises the following steps: 1, adjusting parameters such as fluorescence conversion material concentration and glass cavity thickness according to light source performance requirements; the cesium lead bromide and the cadmium selenide / zinc sulfide are respectively excited by 450nm laser to radiate 521nm light and 632nm light. And 2, fixing the fluorescence conversion material on the reflecting surface of the reflecting mirror so as to improve the transmitting power of the light source. Backward radiated 521nm and 632nm light and unconverted residual 450nm light are reflected by the reflecting mirror and are combined with forward radiated light to generate a white light beam. Thirdly, a radiator is assembled on the back face of the reflector, and the thermal stability of the system is improved. The method is not only suitable for the fields of visible light communication and solid-state illumination, but also provides important technical support for various related applications such as intelligent illumination and indoor wireless communication.

The present invention belongs to the field of optical devices. In order to improve the modulation depth and bandwidth of the modulator, a broadband transmission infrared light modulator based on graphene plasma is proposed, comprising a substrate, a graphene modulation layer is covered on the substrate, a non-metallic grating layer is provided on the modulation layer by coating-etching, a metal grating layer is provided on the non-metallic grating layer by coating, and electrodes 1 and 2 are provided on both sides of the substrate by coating. By coupling the graphene with the non-metallic grating layer, the excellent polarization characteristics of the metal grating and the field confinement capability of further enhancing the graphene localized surface plasmon polaritons are utilized, thereby greatly improving the modulation depth and modulation bandwidth of the device. The structure has strong reflection for TE linearly polarized incident light, and can realize transmission modulation with high modulation depth in a wide band range for TM linearly polarized incident light. This characteristic can realize the modulation function of high modulation depth and wide modulation bandwidth for the transmitted light when natural light is incident.

The application provides a compact high-speed modulator, which comprises an input waveguide, a light splitting structure for splitting light input by the input waveguide into a first light path and a second light path, a first photonic crystal region for modulating the first light path by thermal light, and a second photonic crystal region for modulating the first light path by electro-optic modulation, a third photonic crystal region for modulating the second light path by electro-optic modulation, and a light combining structure for combining the modulated first light path and the second light path and outputting the combined light path through an output waveguide, wherein the first to third photonic crystal regions each comprise a plurality of periodically arranged structure units, each structure unit comprises a one-dimensional topological lattice waveguide and a first multi-lattice expansion region and a second multi-lattice expansion region located on two sides of the one-dimensional topological lattice waveguide respectively, and by modulating the phase shift and the coupling strength at the interface, topological boundary states with different characteristics are excited in the band gap.

The invention discloses a band-pass and band-stop switchable integrated microwave photonic filter based on a film lithium niobate platform. The band-pass and band-stop switchable integrated microwave photonic filter comprises a Mach-Zehnder modulator, a composite structure and a micro-ring resonator, wherein the Mach-Zehnder modulator is integrally manufactured on a film lithium niobate chip; the composite structure is used for adjusting the phase relation between an optical carrier and an optical sideband; according to the invention, the structure is simple, the switching between band-stop filtering and band-pass filtering can be realized through the two micro-ring resonators and the phase shifter, the system complexity is reduced, and flexibility and economical efficiency are realized. According to the invention, the operation is simple, the switching of the filtering function can be realized only by adjusting the voltage of the phase shifter, the dynamic adjustment can be realized according to the actual demand, and the variable application scenarios can be satisfied.

The application relates to the technical field of photoelectric devices, in particular to an RC-Micro LED device and a preparation method thereof, which comprises, from bottom to top, a second substrate, a metal conductive support layer, a metal electrode layer, a first mirror layer, a transparent conductive layer, a gallium nitride epitaxial layer and a second mirror layer; the gallium nitride epitaxial layer is in a convex mesa structure, an insulating layer is covered on the sidewall of the convex mesa structure; the first mirror layer and the second mirror layer are oppositely arranged to form a Fabry-Perot resonant cavity structure. The RC-Micro LED device can meet the transmission requirement of high-speed short-distance optical interconnection.

This application discloses a GaN-based micro-LED epitaxial structure, device, and fabrication method. The GaN-based micro-LED epitaxial structure includes, along the growth direction, a substrate, a buffer layer, an N-type doped GaN electron injection layer, an active region, and an Al2O3 layer. y Ga 1‑y The substrate consists of an N-type electron blocking layer and a P-type doped GaN hole injection layer; the substrate is selected from a (111) crystal plane single-crystal silicon substrate, a c-axis single-crystal sapphire substrate, a c-axis single-crystal silicon carbide substrate, or a c-axis self-supporting single-crystal gallium nitride substrate; the active region includes an InGaN-based light-emitting structure, which is at least one of an InGaN / GaN alternating multi-quantum-well structure, a GaN / InGaN / GaN single-quantum-well structure, and an InGaN quantum dot structure. This application shortens the carrier radiative recombination lifetime, weakens the quantum-confined Stark effect, and improves the radiative recombination rate by employing a thin quantum well or quantum dot active region structure, thereby enhancing the device's modulation bandwidth and photoelectric efficiency, meeting the performance requirements of light sources for applications such as data center optical interconnects, co-packaged optics, and high-speed visible light communication.

The invention discloses a thin film lithium niobate modulator with a stepped three-layer electrode structure and a preparation method. The thin film lithium niobate modulator with the stepped three-layer electrode structure sequentially comprises a substrate layer, a buffer layer, a lithium niobate thin film layer, two lithium niobate ridge waveguides, a metal traveling wave electrode and a dielectric layer from bottom to top, the metal traveling wave electrodes are distributed on the two sides of the two lithium niobate ridge waveguides, adopt a ground-signal-ground push-pull mode and comprise three layers of electrodes, and the lower-layer ground-signal-ground electrode is tightly attached to a substrate area of the lithium niobate ridge waveguides and used for providing uniform initial electric field distribution; the middle-layer ground-signal-ground electrode is wider than the lower-layer ground-signal-ground electrode and is used for adjusting electric field distribution and increasing the conductor area so as to reduce microwave loss; and the upper-layer ground-signal-ground electrode is wider than the middle-layer ground-signal-ground electrode and is used for reducing impedance and enhancing the uniformity of electric field distribution. According to the invention, the modulation bandwidth can be significantly improved while the low half-wave voltage is maintained.

The application discloses a quantum secure networking device and method based on center-pumped frequency comb distribution, relates to the technical field of quantum information, and simultaneously distributes pump laser to each user node through a center-pumped laser distribution unit, so that each user node can independently generate an electro-optical frequency comb; the electro-optical frequency comb generation unit is combined with a thin-film lithium niobate cascade modulator and a capacitively loaded slow-wave electrode structure, so that the half-wave voltage is effectively reduced and the modulation bandwidth is improved; polarization control and photon detection of the encoded comb teeth are performed through two-photon interference and a quantum key distribution unit, and quantum key distribution is realized based on the two-photon interference effect. The above functional modules work in sequence and in cooperation, so that pump light distribution, electro-optical comb generation, filtering and encoding, polarization control and two-photon interference detection form a complete closed loop, high security and high efficiency of quantum key distribution in a multi-user full-connection scene are realized, and the practical application requirements of large-scale quantum secure networking are met.

The present invention discloses a visible light communication method and system based on narrow-band nano-luminescent materials. The visible light communication method adopts a spectrum optimization calculation method to obtain white light emission spectra with the same color but different spectra, and controls white light LEDs to emit multiple emission spectra. Under the condition that the color and luminous intensity of the luminescent light source remain unchanged, the components and proportions of different narrow-band monochromatic emission spectra in the white light LED are modulated, so that the actual communication band and other lighting bands are mixed and emitted. After adopting a filter of a special light band, a photoelectric detector can detect the information carried by the emitted light signal, and decode and obtain the information. Compared with radio frequency communication and ordinary visible light communication methods, the present invention effectively protects the data transmitted in visible light communication, accurately senses the changes of the alternating dark and bright light of a specific wavelength, realizes the integration of communication and sensing, and has the characteristics of deep modulation, high efficiency, high confidentiality, and expandable application scenarios.

The present invention discloses a chip integrated communication sensor signal integrated processing method based on a coating structure, wherein a voltage-sensitive two-dimensional layered material coating is coated on the surface of a chip integrated waveguide and a modulation voltage carrying a high-speed communication signal is applied, and the communication signal loading of the transmission light field is realized by adjusting the refractive index of the chip integrated waveguide by changing the free carrier concentration; the low-frequency sensing signal is loaded on the high-frequency communication signal using the all-optical communication signal as a carrier and the environmental variable sensitive two-dimensional layered material coating as a carrier; the sensing signal and the communication signal are demodulated respectively, thus realizing the integrated processing of the communication sensing signal. The present invention makes full use of the performance advantages of the coating structure in high-performance electro-optical modulation and high-sensitivity environmental sensing, effectively expands the functional scope of a single chip integrated optical circuit, and provides a solution for miniaturized, tightly coupled communication sensing integrated equipment.

An electro-optic modulator (210), an optical module (201), and an optical transmitting device (110) are provided to reduce an optical loss in a process of modulating an optical signal and improve modulation efficiency when maintaining a high modulation bandwidth. The electro-optic modulator (210) includes a first electrode and a second electrode that are located on a surface of a base board. The electro-optic modulator (210) further includes a transmission optical waveguide (216). An electric field between the first electrode and the second electrode is used to modulate an optical signal transmitted by the transmission optical waveguide (216). The first electrode includes a first conducting layer (231) and a second conducting layer (232), and the second conducting layer (232) is located between the base board and the first conducting layer (231). An electrical conductivity of the first conducting layer (231) is greater than an electrical conductivity of the second conducting layer (232), and an optical-absorption coefficient of the first conducting layer (231) is greater than an optical-absorption coefficient of the second conducting layer (232).

The invention provides an electro-optical modulator, which is applied to the technical field of optical fiber communication, and comprises an input optical waveguide used for optical signal injection; the first coupler is used for equally dividing the optical signal into two beams of optical signals with equal power; the phase modulation arm is used for changing the phase of the optical signal; wherein the phase modulation arm is provided with a phase change material, and the phase change material is reversibly converted between a crystalline state and an amorphous state; the traveling wave electrodes are arranged on the two sides of the phase modulation arm and used for changing the refractive index in the phase modulation arm under the action of an electric field; the second coupler is used for combining the interference light output by the phase modulation arm; and the output optical waveguide is used for outputting the interference light after beam combination. According to the electro-optical modulator, the phase-change material is arranged on the branch waveguide, and the phase-change material is reversibly converted between a crystalline state and an amorphous state by applying pulsed light, so that the light intensity passing through the branch is changed, the modulation function is dynamically switchable, and the functionality of a single modulator is effectively improved.

The invention relates to the technical field of silicon-based integrated photoelectronics, and particularly discloses a silicon-based electro-optical modulator with an enhanced modulation bandwidth and a manufacturing method of the silicon-based electro-optical modulator. According to the traveling wave electrode structure, the effective refractive index is reduced through the specific electrode width W and the specific electrode distance D, phase velocity matching of light waves and microwaves is achieved, and therefore the modulation efficiency and the bandwidth are improved; the ridge waveguide structure optimizes the overlapping degree of an optical mode and a microwave mode by adjusting the ridge height H and the width B, and carrier absorption loss is reduced; the electro-optical modulator adopts the periodically loaded coplanar waveguide traveling wave electrode, so that the refractive index is effectively reduced, phase velocity matching of light waves and microwaves is realized, and the modulation efficiency and the bandwidth are remarkably improved. Meanwhile, by introducing the ridge-shaped waveguide structure and accurately adjusting the size parameter of the ridge-shaped waveguide structure, the overlapping degree of an optical mode and a microwave mode is optimized, the carrier absorption loss is reduced, and the device performance is further improved.

The laser chip fabrication method and laser chip disclosed herein include a light-emitting region and an electro-absorption modulation region. The P-InP layer includes a first region, a second region, and a third region, with a second active region located below the third region. The first and second regions are exposed to the implanted ion beam, forming a first and a second electrically isolated region. The third region, protected by a mask, remains conductive, forming a first P-InP body layer. During ion implantation, the first and second metal layers act as masks for the first P-InP body layer, intercepting ion implantation and preventing ions from penetrating deep into the first P-InP body layer, thus maintaining its conductivity. The narrow linewidths of the first and second metal layers reduce the ion implantation width of the first P-InP body layer, resulting in a narrower linewidth first P-InP body layer, which is beneficial for improving the modulation rate and modulation bandwidth of the electro-absorption modulation region.

The present invention discloses a chip-integrated communication detection signal integrated processing method based on a coating structure, wherein a voltage-sensitive two-dimensional layered material is coated on the surface of a chip-integrated waveguide and a modulation voltage carrying a high-speed communication signal is applied, and the communication signal loading of the transmission light field is realized by adjusting the waveguide refractive index through electro-induced free carriers; a photosensitive two-dimensional layered material is coated on the surface of a chip-integrated waveguide and receives light intensity irradiation, and the detection signal loading of the transmission light field is realized by adjusting the waveguide refractive index through photo-generated free carriers; the communication signal and the detection signal are combined and transmitted through orthogonal polarization, that is, the integrated processing of the communication detection signal is realized through a single optoelectronic chip. The present invention makes full use of the performance advantages of the coating structure in high-performance electro-optical modulation and high-sensitivity photoelectric effect, and realizes the integrated integration of the communication detection dual system through a single chip, which is a miniaturized, tightly coupled multifunctional terminal device for the Internet of Things.

The invention discloses an electro-optical modulator and a preparation method thereof. The electro-optical modulator comprises an electro-optical material film wafer; the covering belt is arranged on the upper surface of the electro-optical material film wafer and is used for restraining a transverse electric mode; the traveling wave electrodes are arranged on the upper surface of the electro-optical material film wafer and located on the two sides of the covering belt. According to the invention, the preparation of the high-performance electro-optical modulator on the non-etching electro-optical material film is realized.

The invention relates to a chip packaging structure, and relates to the technical field of packaging, and the chip packaging structure comprises a substrate, and a transmission line and a chip which are located at one side of the substrate and are arranged at an interval; the connecting bridge structure comprises a first connecting part and a second connecting part which are connected with each other; the first connecting part is connected with the transmission line, and the second connecting part is connected with the chip. According to the chip packaging structure, the transmission line and the chip are connected by adopting the first connecting part and the second connecting part of the connecting bridge structure, and the width of the first connecting part in the first direction is greater than the preset width, so that the parasitic inductance between the chip and the transmission line is reduced. The parasitic inductance and the capacitance of the chip can generate a resonance effect, the parasitic inductance between the transmission line and the chip is reduced, the generated resonance effect can increase the modulation bandwidth of the chip packaging structure, and the use rate of the chip packaging structure is further increased.