11results about How to "High extinction ratio" patented technology

This invention relates to a quadrilateral photonic crystal fiber filter based on dual-wavelength filtering, belonging to the field of fiber optics and photonic device technology. It includes a substrate and a fiber core disposed within the substrate, and a cladding surrounding the fiber core. The cladding contains multiple layers of air holes extending along the fiber axis, arranged periodically in a two-dimensional quadrilateral lattice. A metal thin film is disposed within the cladding to excite surface plasmon resonance (SPR). At least one non-circular air hole is also disposed within the cladding to enhance the birefringence of the fiber. The multiple air holes, metal thin film, and non-circular air holes enable the filter to selectively filter orthogonal polarization states in two different communication bands. This invention, based on SPR and employing a quadrilateral lattice structure, achieves polarization-selective filtering in two communication bands and exhibits good tolerance to manufacturing errors; simultaneously, its regular structure makes it easy to manufacture.

This invention proposes a dual-channel hexagonal lattice photonic crystal non-volatile optical switch based on resistive switching effect. It includes a photonic crystal waveguide with a TE bandgap, disposed on a photonic crystal. Several silicon dielectric pillars are arranged on the photonic crystal, with the waveguide positioned between them. The input waveguide has an input port, and the output waveguide has two output ports with opposite directions. A resonant cavity is located between the input port and the two output ports. A defective dielectric pillar is located within the resonant cavity, with electrodes coated with electrochemical metal at both ends. These electrodes are connected to a bias circuit. Due to the resistive switching effect, when a voltage is applied across the defective dielectric pillar, conductive filaments are formed inside, thereby adjusting the resonant frequency of the resonant cavity and controlling the switching of the signal light. This invention is easy to array, has a small structure size, fast switching time response, high optical transmission efficiency, and is non-volatile.

This application relates to the technical field of optical thin films, specifically disclosing a high extinction ratio linear polarizing film and its preparation method. The film comprises a multilayer stacked structure with alternating high-refractive-index optical layers and low-refractive-index optical layers. The high-refractive-index optical layer is made of polyethylene terephthalate modified with 4,4'-biphenyl dicarboxylic acid monomer, wherein the molar content of BB monomer is 15%-35%. At a wavelength of 550 nm, the three-dimensional refractive index of the high-refractive-index optical layer satisfies: n y With n z The difference Δn yz ≤0.01, where n y n is the longitudinal refractive index. z Here, n represents the refractive index in the thickness direction. This application involves longitudinal stretching, followed by transverse stretching and simultaneous longitudinal shrinkage, thereby increasing the n of the high refractive index layer. y and n z Adjusting the values ​​to be very close to match the truly isotropic low refractive index layer effectively eliminates polarization chromatic aberration and rainbow patterns caused by refractive index mismatch.

This invention discloses a broadband infrared polarizer based on a germanium substrate and its fabrication method, belonging to the field of infrared optical device technology. The polarizer comprises a germanium substrate, a buffer layer, an ultrathin metal thin film layer, a dielectric spacer layer, a two-dimensional material metal composite metasurface layer, and a dielectric protective layer, stacked sequentially. An infrared antireflection coating is provided on the surface of the germanium substrate. The ultrathin metal thin film layer serves as a transparent electrode, and the two-dimensional material metal composite metasurface layer contains a metal nanoantenna array and a two-dimensional material layer covering it. By precisely designing the thickness of the dielectric spacer layer, a resonance enhancement effect is formed in the infrared band, improving the polarization extinction ratio and operating bandwidth. This invention also provides a corresponding fabrication method with strong process compatibility, suitable for mass production. This polarizer exhibits high transmittance, wide-band operation, high extinction ratio, and electrical tuning capability in the 412-micron band, making it suitable for systems such as infrared imaging, spectral detection, and free-space optical communication.

The application provides a single-channel photonic crystal nonvolatile optical switch of electrochemical metallization, and aims at solving the technical problems of large power consumption and volatility of the existing photonic crystal optical switch.The application comprises a photonic crystal composed of a plurality of silicon dielectric columns, a photonic crystal waveguide with a TE forbidden band is arranged between the silicon dielectric columns, an input port of the input photonic crystal waveguide is an input end, an output port of the output photonic crystal waveguide is an output end, the input end and the output end are perpendicular to each other, a resonant cavity is arranged between the input photonic crystal waveguide and the output photonic crystal waveguide, a defect dielectric column is arranged in the resonant cavity, and the defect dielectric column is connected with a bias circuit for providing a bias voltage.The application has the advantages of small structure size, fast switch time response, high optical transmission efficiency, and suitability for large-scale optical path integration; and the application is convenient to integrate, and can realize the electrically-controlled optical switch of the TE carrier optical signal in a short distance and with high efficiency.

The invention discloses a low-crosstalk long-distance sensing integrated device and a very-low-frequency sensing method, and relates to the technical field of fusion of optical fiber sensing and optical fiber communication. The device comprises a laser, a coupler, a communication modulation device, a sensing modulation device, an optical fiber transmission and relay link, a communication receiving device, a sensing receiving device and a signal processing device. The communication modulation device adopts digital subcarrier multiplexing and reserves a guard interval in a frequency spectrum center, and residual carrier filtering is combined to reduce the inductance crosstalk; the sensing modulation device realizes high-extinction-ratio pulses through a cascade light modulator, and the signal-to-noise ratio is improved. The optical fiber link adopts a bidirectional amplification relay module to synchronously amplify forward and backward signals so as to realize ultra-long distance transmission. The signal processing device carries out high-density sampling and space-time dimension fusion on the sensing beat frequency signals, and very low frequency vibration information is effectively extracted. According to the invention, common-light-source, low-crosstalk, long-distance, very-low-frequency and high-sensitivity integrated transmission and detection of communication and sensing signals are realized.

The present application relates to a kind of deep ultraviolet grating polarizers and preparation method thereof, belong to polarizer technical field, including from bottom to top sequentially connected substrate, first dielectric layer, second dielectric layer and interval setting line grid on the upper surface of second dielectric layer, the upper surface of second dielectric layer between adjacent line grid is provided with metal layer, line grid includes from bottom to top sequentially connected first dielectric layer, second dielectric layer and metal layer;The present application is by adding high low refractive index alternately between substrate and metal line grid first, second dielectric layer, and metal layer is set on the upper surface of second dielectric layer in line grid gap, constructs the medium-metal composite structure with resonance coupling effect.The design effectively controls the equivalent optical admittance of deep ultraviolet band, significantly enhances the transmittance of TE polarized light, while maintaining the efficient inhibition to TM polarization, so as to improve the polarization efficiency while reducing metal absorption loss.As a whole, the polarizer has the advantages of high transmittance, high extinction ratio and the like.

The application provides an electro-optical modulator and an optical quantum computer, and relates to the technical field of electro-optical modulation.The electro-optical modulator comprises a waveguide optical path structure, a direct current bias structure and a radio frequency modulation structure.The waveguide optical path structure comprises an input end optical waveguide, a light splitting waveguide, a first modulation arm, a second modulation arm, a beam combining waveguide, a curved waveguide and an output end optical waveguide connected in sequence.The output end optical waveguide is arranged side by side with the input end optical waveguide and is connected with the curved waveguide.The direct current bias structure is arranged on the two sides of the first modulation arm.The radio frequency modulation structure is arranged on the two sides of the first modulation arm and the two sides of the plurality of second modulation arms.The light signal directions of the input end optical waveguide and the output end optical waveguide are opposite.Compared with the prior art, the application can realize the same side coupling of the input and output optical ports, the overall size is smaller, the degree of integration is higher, the light directly entering the light outlet port is avoided, the optical crosstalk is reduced, the extinction ratio is improved, and the optical signal transmission effect is improved.

The light splitting assembly, the light splitter and the optical quantum computer provided by the present application comprise a light mode conversion waveguide assembly, a light mode separation assembly and a light signal filtering assembly. The mode conversion waveguide assembly is configured to receive an incident light signal containing multiple modes, and convert a first part of the light signal transmitted in a first type of mode in the incident light signal into a light signal transmitted in a third type of mode. The light mode separation assembly is configured to receive and separate the light signal transmitted in the third type of mode and a light signal transmitted in a second type of mode from a second part of the light signal transmitted in the first type of mode, and convert a third part of the light signal transmitted in the third type of mode into a light signal transmitted in a fourth type of mode. The light signal filtering assembly is configured to receive and filter out the second part of the light signal transmitted in the first type of mode which is not converted after passing through the light mode conversion waveguide assembly, and the fourth part of the light signal transmitted in the third type of mode which is not converted after passing through the light mode separation assembly.

This invention discloses a graphene-based silicon waveguide polarization filter, comprising a silicon substrate, a silicon dioxide lower cladding, a silicon waveguide, a polymer waveguide, and a silicon dioxide upper cladding, arranged sequentially; the polymer waveguide contains graphene. The graphene concentration ranges from 0.1 mg / ml to 1 mg / ml. A method for fabricating the graphene-based silicon waveguide polarization filter is also disclosed. First, a silicon dioxide lower cladding is fabricated on the upper surface of the silicon substrate. Then, a silicon thin film is fabricated on the upper surface of the silicon dioxide lower cladding. The silicon thin film is then patterned to form a silicon waveguide. Graphene is incorporated into EPO polymer photoresist, and a graphene-containing polymer waveguide is fabricated on the upper surface of the silicon waveguide. Finally, a silicon dioxide upper cladding is fabricated on the surface of the graphene-containing polymer waveguide. This invention enables precise control and patterning of the position, thickness, and size of the graphene-containing polymer waveguide, making it suitable for the precise and efficient fabrication and widespread application of polarization filters.

The application discloses a TM mode polarizer based on a cascaded antisymmetric multimode Bragg grating structure, which comprises an input waveguide group, a first grating, a connecting waveguide group, a second grating and an output waveguide group which are sequentially connected along a transmission direction, a plurality of columns of period units are arranged in the first grating and the second grating respectively, a displacement difference is arranged between two adjacent columns of period units in a horizontal direction, and the periods of the first grating and the second grating are not equal. The application has the advantages of compact structure, large working bandwidth, low insertion loss in an effective working bandwidth and high extinction ratio. Two antisymmetric multimode Bragg gratings with different periods are cascaded to convert input TE0 mode signal light into reversely transmitted TE1 mode, the reversely transmitted TE1 mode is leaked into a cladding through a tapered waveguide, input TM0 mode signal light is directly transmitted through the waveguide without being affected, and finally, low-insertion-loss, high-extinction-ratio and large-bandwidth TM0 mode light signals are obtained at an output end of a single-mode output waveguide.