48results about How to "Low polarization dependent loss" patented technology

A reduced polarization-dependent loss optical device utilizing two or more dispersive elements or a single dispersive element and a turning mirror, wherein the optical signal makes two passes through said single dispersive element when reflected from said turning mirror, and wherein the two or more dispersive elements or double pass single dispersive element has lower dispersion compared to a functionally equivalent single dispersive element, resulting in lower polarization dependent loss, reduced chromatic dispersion and increased wavelength dispersion. Moreover, a wavelength selective switch incorporating the optical device utilizing aperture-shared optics and functionally distinct planes of operation that enables high fiber port counts, such as 1×41, and multiplicative expansion, such as to 1×83 or 1×145, by utilizing elements optimized for performance in one of the functionally distinct planes of operation without affecting the other plane.

A transmission grating that provides low polarization dependent loss over a wide wave range and provides high diffraction efficiency even with a small groove pitch and high resolving power and dispersion.

In a transmission grating 10, multiple parallel ridges 22 that are transparent for the wave range to be used are disposed on one side of a substrate 20 that is transparent for the wave range to be used. Parallel grooves 24 are formed at a fixed pitch a between these ridges. Light is applied from the surface of the transmission grating on which the grooves are formed and diffracted light is extracted from the substrate surface on which grooves are not formed. The groove pitch a is set to a range of 0.51 λc-1.48 λc, where λc is the central wavelength.

The invention provides a method for designing a T-shaped groove grating structure. An output coupler is realized by adopting different coupling principles for two modes so as to realize efficient coupling output by adopting the same structure for a TE mode and a TM mode simultaneously. The coupling efficiencies of the TE mode and the TM mode within a wavelength range of 1,480 to 1,580nm are both above 50 percent; and the coupling efficiencies of the two modes reach 58 percent when the wavelength is 1,550nm. The polarization dependent loss (PDL) of the coupler within a wavelength range of 1,510 to 1,580nm is less than 0.05dB and the PDL of the coupler is only 3.6*10<-3>dB when the wavelength is 1,550nm. The designed grating coupler realizes a coupling output function with high coupling efficiency, low polarization dependent loss and high bandwidth, has the advantages of simple structure, convenient manufacturing and small volume, is compatible with a standard CMOS process, and can provide technical support for the design and manufacturing of a polarization-independent device.

The invention discloses a terahertz photonic crystal fiber coupler. Including cladding and core, the core is three, surrounded by the inner air hole (3) at the apex of the regular hexagon, wherein the first core (4) is formed by the center of the matrix material (1) , the second core (5) and the third core (6) are symmetrically located on both sides of the first core (4); the network of outer air holes (2) is located around the inner air holes, and the adjacent holes are equally spaced; the first fiber core (4) is the input end, the second fiber core (5) and the third fiber core (6) are the output ends; the inner air hole (3) Same as the hole period Λ of the outer layer air holes (2), the relationship between the diameter d1 of the outer layer air holes (2) and the diameter d2 of the inner layer air holes (3) satisfies d1≥d2. The invention has the advantages of working in a wide wavelength range, stable output, low transmission loss and polarization-dependent loss, and the like.

The invention discloses an array waveguide grating structure based on a PLC (programmable logic controller) technique and a manufacturing method thereof. The manufacturing method comprises the following steps of: selecting a substrate, depositing and growing a B and P doped silica layer as a lower coating layer on the selected substrate by adopting a PECVD (plasma enhanced chemical vapor deposition) process; growing a waveguide core layer on the lower coating layer; preserving a waveguide core in a preset shape on the waveguide core layer, and corroding to remove the part except the waveguide core in the preset shape and to remain the waveguide core in the preset shape; and growing a B and P highly doped silica layer capable of completely covering the lower coating layer and the waveguide core as an upper coating layer on the lower coating layer and the waveguide core, so that the needed array waveguide grating structure based on the PLC technique is manufactured. By using the array waveguide grating structure based on the PLC technique and the manufacturing method thereof, which are provided by the invention, the defects of long growth period, high cost, bad product performance and the like in the prior art can be overcome, so as to realize the advantages of short growth period, low cost and good product performance.

The invention relates to a low polarization dependent loss lithium niobate straight-bar waveguide phase modulator and a manufacturing method of the low polarization dependent loss lithium niobate straight-bar waveguide phase modulator. The low polarization dependent loss lithium niobate straight-bar waveguide phase modulator comprises a lithium niobate optical waveguide chip, a first polarization-maintaining pigtail assembly and a second polarization-maintaining pigtail assembly, wherein the first polarization-maintaining pigtail assembly and the second polarization-maintaining pigtail assembly are bonded to the two ends of the lithium niobate optical waveguide chip in a coupling mode respectively, the lithium niobate optical waveguide chip comprises a lithium niobate substrate, a titanium diffusion waveguide area, annealing external diffusion areas and metal electrodes, an x-cut y-pass chip is adopted for the lithium niobate substrate, the titanium diffusion waveguide area and the annealing external diffusion areas are arranged on the surface layer of the lithium niobate substrate, the annealing external diffusion areas are arranged on the two sides of the titanium diffusion waveguide area respectively, the metal electrodes are arranged on the surfaces of the annealing external diffusion areas, the positive electrode and the negative electrode are symmetrical about the titanium diffusion waveguide area, and the first polarization-maintaining pigtail assembly and the second polarization-maintaining pigtail assembly respectively comprise a first polarization-maintaining optical fiber and a first optical fiber fixing block. The low polarization dependent loss lithium niobate straight-bar waveguide phase modulator achieves low insertion loss and low polarization dependent loss of a device at the same time, and achieves power even distribution of two polarization states, the situation of modulation waveform distortion is effectively eliminated, and accuracy of electro-optical modulation is improved.

The invention discloses a full optical fiber integrated optical power monitor and a manufacture method thereof. The full optical fiber integrated optical power monitor comprises an optical power monitor and a variable optical attenuator; a cladding of a section of optical fiber is provided with a first light splitting notch and a second light splitting notch between which the distance is 5-25mm; the first light splitting notch is a leakage light path of the variable optical attenuator; and the second light splitting notch is a leakage light path of the optical power monitor. The full optical fiber integrated optical power monitor is manufactured by a side polishing method, the processing cost is low, and the full optical fiber integrated optical power monitor is taken as an integrated substrate, so that the cost of an integrated device is greatly reduced. The full optical fiber integrated optical power monitor has the advantage of capability of being controlled electrically, saves an optical fiber core cutting and mechanical driving mechanism of a mechanical optical power monitor, has low inserting loss and small back reflection electrode, improves reliability of the device and reduces the packaging volume of the device.

The invention belongs to the optical passive device technical field, relating to a method for producing a high power variable optical attenuator. A metallic thin film loophole is produced on a glass substrate and the fenestration varies gradually along the length of the substrate, thus the attenuation of optical power varies gradually along the length of the substrate. The metallic thin film loophole is produced by stripping the metals. In the invention, the metallic thin film loophole does not need to be produced by wet or dry etching technique, the production technique is simple, and the reproducibility is good; the metallic thin film of the surface can be any one layer or a plurality of layers of metallic materials, thus the thin film is not limited by the wet or dry etching technique on materials; and the edge of the metallic little hole of the finished attenuator is smooth, and the rate of finished products of the device is high.

The invention relates to the technical field of optical wavelength division multiplexing, and in particular relates to a thermal compensation optical wave multiplexing and demultiplexing chip and a preparation method thereof. The thermal compensation optical wave multiplexing and demultiplexing chip provided by the invention comprises an input array waveguide, an input star coupler, an array waveguide, an output star coupler and an output array waveguide; a thermal compensation structure is arranged on the input star coupler, and a trench grating is processed through a semiconductor process; and negative thermal expansion coefficient silica gel is filled in the trench grating. According to the thermal compensation optical wave multiplexing and demultiplexing chip and the preparation methodthereof, the grating structure is etched on the input star coupler and is filled with a negative refractive index material to achieve temperature drift compensation; and the chip is free of stress control and fragmentation, and has the advantages of easy integration manufacture, compact structure, low transmission loss, uniform insertion loss, low polarization-dependent loss and the like.

The invention discloses a single-fiber bidirectional receiving and sending device based on pentagonal prism and interference filter, belonging to the technical field of optical fiber communication. The single-fiber bidirectional receiving and sending device comprises a laser transmitter, a laser detector, an optical fiber component and the pentagonal prism, wherein the pentagonal prism comprises afirst side face, a second side face and a third side face arranged corresponding to each part above, and a fourth side face used for performing total reflection for a light beam, wherein the first side face is provided with the filter. In the device provided by the invention, the pentagonal prism is added in an optical path, thus, optical path of incident light is changed before entering into thefilter, an incident angle (5-30 degrees) of the incident light is changed, and polarization dependent loss of a system is reduced; meanwhile, an included angle Beta between the first side face I andthe fourth side face IV is designed suitably, thus, the second beam of output light is perpendicular to the incident light, which meets a standard of an optical transceiver. The device provided by theinvention enables each index of such structure product to meet requirements under the premise of guaranteeing size, and improves functions of the transceiver.

The invention provides a wavelength-selective optical switch, which comprises a polarization beam-splitting unit and a wavelength selection unit. The wavelength selection unit includes a polarizationbeam splitting unit used for splitting an input light beam into a first polarized light beam and a second polarized light beam, transmitting the first polarized light beam to the input end of a firstgroup of micro-ring resonators and transmitting the second polarized light beam to the input end of a second group of micro-ring resonators. The first group of micro-ring resonators is used for coupling a first target beam in the first polarized light beam to the first group of micro-ring resonators, and outputting the first target beam output to a polarization beam-combining unit. The second group of micro-ring resonators is used for coupling a second target beam in the second polarized light beam to the second group of micro-ring resonators, and outputting the second target beam output to the polarization beam-combining unit. The polarization beam-combining unit is used for combining the first target beam and the second target beam. In this way, the polarization state conversion of the first polarized light beam and the polarization state conversion of the second polarized light beam are the same in number of times. The polarization-related loss is lowered.

The invention discloses a photonic crystal fiber directional coupler. Host material (1), holes (2) and holes (3) form fiber cores and a cladding, wherein the holes (2) and the holes (3) are formed in the host material (1). Centers of the holes (2) and the holes (3) are respectively located on nodes of a right triangle structured grid. The number of the fiber cores is three, where the first fiber core (4) is arranged on a center area of the host material (1), the right triangle structured grid misses a hole to from the first fiber core (4), the second fiber core (5) and the third fiber core (6) are symmetrically located on two sides of the first fiber core (4), the right triangle structured grid respectively misses a hole to from the fiber core (5) and the fiber core (6), air holes around innermost layers of the fiber core (5) and the fiber core (6) are the holes (2) and the holes (3), and the relationship of the diameter d2 of the holes (3) and the diameter d1 of the holes (2) satisfies that d2 >=d1. According to the photonic crystal fiber directional coupler, the diameters of the cladding air holes (3) of the fiber cores (the fiber core (5) and the fiber core (6)) on two sides are changed, and the advantages of being wide in wavelength coverage operation, insensitive to the fiber length and low in transmission loss and polarization relevant loss and other advantages are achieved.

The invention discloses an optical-phase conjugation mirror device. The device comprises optical fibers, a polarization spectrometer, a lens, a Faraday rotator and a reflecting mirror; Gaussian divergent light beams emitted from the optical fibers pass through the polarization spectrometer, the lens, the Faraday rotator and the reflecting mirror in sequence, are reflected by the reflecting mirror,then pass through the Faraday rotator, the lens and the polarization spectrometer and are returned to the optical fibers; two light beams divided by the polarization spectrometer deflect and convergethrough the lens, are reflected by the reflecting mirror and then transmitted in the reverse direction of the path of the opposite side, pass through the Faraday rotator again and enter the polarization spectrometer in the reverse direction, and the two light beams are recombined in space and enter the optical fibers. According to the optical-phase conjugation mirror device, nonreciprocal 90-degree angle polarization rotation which is irrelevant to the wavelength and temperature is achieved, the structure is compact, simple and reliable, and meanwhile the optical performance of high extinction ratio, low polarization related loss and low insertion loss is also kept.

The invention discloses a spot-size converter and a silicon optical integrated chip. The spot-size converter has a first end surface optically coupled with an external optical fiber and a second end surface optically coupled with an external optical device, and the spot-size converter comprises a first optical waveguide and a second optical waveguide, wherein the first optical waveguide comprises a first wedge-shaped structure and a second wedge-shaped structure, and the first wedge-shaped structure and the second wedge-shaped structure face opposite directions; and the second optical waveguide comprises a third wedge-shaped structure, and the tip of the third wedge-shaped structure faces the first wedge-shaped structure and is at least partially overlapped with the second wedge-shaped structure. By designing a special waveguide coupling structure, the mode matching degree of the spot-size converter and the external optical fiber is improved, the polarization dependent loss between the two optical waveguides in the spot-size converter is reduced, and the thermal stability of the optical waveguides in the silicon optical integrated chip is improved, so that the optical transmission loss in the silicon optical integrated chip is reduced.

The invention discloses a miniature magneto-optical fiber switch, consisting of a miniature three-fiber collimator, a miniature current coil and a miniature space light processing optical kernel. Theminiature fiber switch with a 1*2 structure and a 2*1 structure is realized by controlling the current direction of the current coil, and the input and output fibers of the miniature magneto-optical fiber switch are located on the same side. The scheme of the invention adopts the three-fiber collimator and the miniature space light processing optical kernel, realizes the micro-structured magneto-optical fiber switch which can simultaneously implement various switching working modes, and has the advantages of multiple working modes, simple structure, ultra-small size, low insertion loss, low polarization-dependent loss, single-sided fiber output, ultra-high channel switching repeatability and ultra-high lifetime.

The invention discloses an active polarization rotator realized based on a mixed surface plasma groove waveguide. The active polarization rotator comprises a power beam splitter, an MZI phase modulation unit, a polarization rotation control unit and a beam combiner. The polarization rotation control unit comprises a mixed surface plasma groove waveguide. The mixed surface plasma groove waveguide has a certain groove width, two dielectric waveguides of the mixed surface plasma groove waveguide have a certain width, and two sides of the mixed surface plasma groove waveguide are respectively provided with a material which has a certain thickness, length and width and has metal characteristics at a certain interval. The active polarization rotator has the advantages that the structure is simplified, the polarization conversion loss is small, and the active regulation and control of the polarization state of the output light can be realized for the incident light of two different polarization states.