1041 results about "Lithium niobate" patented technology

The invention relates to an optical device including a passive high confinement waveguide, such as of silicon-rich silicon nitride, on an electro-optic substrate, like lithium niobate, optically coupled to a waveguide in the electro-optic substrate. A wide range of electro-optic devices are enabled by this high confinement waveguide structure, including: directional couplers, compact tap couplers, folded electro-optic devices, electro-optic modulators including ring resonators, electro-optic gratings. Further applications enabled by the present invention include hybrid passive planar lightwave circuits (PLC) integrated with electro-optically active waveguides, using the high confinement waveguide as an intermediary waveguide to transfer optical power between the passive and active components.

An optical parametric oscillator (OPO) is described that efficiently converts a near-infrared laser beam to tunable mid-infrared wavelength output. In some embodiments, the OPO includes an optical resonator containing a nonlinear crystal, such as periodically-poled lithium niobate. The OPO is pumped by a continuous-wave fiber-laser source having a low-power oscillator and a high-power amplifier, or using just a power oscillator). The fiber oscillator produces a single-frequency output defined by a distributed-feedback (DFB) structure of the fiber. The DFB-fiber-laser output is amplified to a pump level consistent with exceeding an oscillation threshold in the OPO in which only one of two generated waves (“signal” and “idler”) is resonant within the optical cavity. This pump source provides the capability to tune the DFB fiber laser by straining the fiber (using an attached piezoelectric element or by other means) that allows the OPO to be continuously tuned over substantial ranges, enabling rapid, wide continuous tuning of the OPO output frequency or frequencies.

Methods and apparatus for reducing the coherence of an optical signal that is used to interrogate optical interferometric sensors are disclosed. The optical field phasor of the interrogation source is modulated in a controlled manner to produce a broadened optical source power spectrum at the output of the source unit. The output from the source unit is launched into an optical sensor network, comprising a multiple of optical pathways from its input to the detection unit, where pairs of optical pathways form sensor interferometers. A compensating interferometer with delay difference similar to the sensor delay difference may be arranged in a serially coupled manner with the optical sensor network, either before or after the network. The optical output power from the source unit may either be continuous or pulsed with a pulse duration similar to the sensor delay. The coherence modulation may be performed through direct modulation of the source or through external modulation of the light with piezoelectric ring modulator, a Lithium niobate phase or intensity modulator, or an acoustooptic modulator.

The present invention provides a delay line SAW device fabricated on a lithium niobate substrate and coated with a bilayer of nanocrystalline or other nanomaterials such as nanoparticles or nanowires of palladiumn and metal free pthalocyanine which will respond to hydrogen gas in near real time, at low (room) temperature, without being affected by CO, O₂, CH₄ and other gases, in air ambient or controlled ambient, providing sensitivity to low ppm levels.

The invention discloses a device and method for generating eight frequency multiplication millimeter waves by utilizing a Mach-Zehnder modulator, and the device and method are mainly used for the generation of the optical millimeter waves in a radio over fiber (ROF) access network. The method is shown in attached figures: optical millimeter wave signals, the frequency of which is eight times as large as that of local oscillator signals, are generated by utilizing nonlinear characteristics and interference superposition characteristics of two parallelly-connected double-parallel lithium niobate Mach-Zehnder modulators (DPMZM) and under the condition of an appropriate DC bias voltage, thereby greatly reducing equipment frequency index required for generating high frequency/ extremely high frequency signals, and reducing the system cost. According to the device and method, specific phase modulation index is not needed, and radio-frequency signals can be flexibly adjusted, so that the requirement for radio-frequency power is lowered; and meanwhile, stray sideband can be well restrained.

The invention relates to a silicon nitride-lithium niobate heterogeneous integrated waveguide device structure and a preparation method of the same. The silicon nitride-lithium niobate heterogeneous integrated waveguide device structure is characterized in that a silicon nitride waveguide in a silica coating layer and a lithium niobate film on the upper surface of the silicon nitride waveguide areheterogeneously integrated to form a ridge waveguide; a traveling wave electrode is arranged on the upper surface of the lithium niobate film; the silicon nitride waveguide is crossed and coupled with the lithium niobate film on the upper surface of the silicon nitride waveguide, and a high speed electric signal is applied to the traveling wave electrode to control the phase of the light wave passing through the lithium niobate film to realize conversion from amplitude modulation of the loaded electric signal to phase modulation of an optical signal; and three-dimensional vertical integrateddesign is utilized to enable integration of the chip to be more compact, so that the space is saved; at the same time insertion loss of the light waveguide can be reduced; 100G light modulation rate can be realized; high speed modulation of the light wave in the lithium niobate film can be realized and the characteristic of low loss propagation through the silicon nitride waveguide is realized; and light modulation with excellent performance is completed. The manufacturing technology of the silicon nitride-lithium niobate heterogeneous integrated waveguide device structure is compatible with the semiconductor processing technology, is high in the modulation efficiency and low in energy consumption, and has important application prospects in the optical signal processing field and other fields.

A polarization-insensitive integrated wavelength converter system includes polarization-separating, polarization-rotating and wavelength-converter structures integrated into a monolithic optical structure. In one embodiment, a lithium niobate waveguide structure includes an integrated polarization separator which comprises two coupled Zinc-diffused and annealed-proton-exchanged waveguides, an electro-optic quarter-wave retarder, a mirror structure and a quasi-phasematching structure. In another embodiment, an electro-optic half-wave retarder and bent waveguide are used in place of the electro-optic quarter-wave retarder and mirror structure. In a further embodiment, an optical circulator is used in conjunction with the waveguide structure in order to discriminate between input and output optical signals.

An elastic wave device includes a lithium niobate film, a supporting substrate, a high-acoustic-velocity film located on the supporting substrate and configured so that the acoustic velocity of a propagating bulk wave is higher than the acoustic velocity of an elastic wave that propagates on the lithium niobate film, a low-acoustic-velocity film stacked on the high-acoustic-velocity film and configured so that the acoustic velocity of the propagating bulk wave is lower than the acoustic velocity of the bulk wave that propagates in the lithium niobate film, the lithium niobate film being stacked on the low-acoustic-velocity film, and an IDT electrode located on either side of the lithium niobate film. When the lithium niobate film has Euler angles of (0°±5°, θ, 0°), θ is in the range of about 0° to about 8° and about 57° to about 180°.

The invention belongs to the technical field of tools for lithium chips and particularly relates to a production process of 6-inch lithium niobate or lithium tantalite chips. The production process includes the steps of A, cutting to obtain chips 0.6-1mm in thickness; B, charging the chips into a reduction furnace for reduction; C, after grinding, cleaning by ultrasonic; D, pasting the chips; E, grinding; F, polishing; G, cleaning, and boxing. Internal stress of the chips is removed by double corroding, electrostatic charge is removed from the chips by blackening, ultra-smooth planes are obtained by mechanical chemical polishing, TTV is smaller than 5 um, BOW is smaller than 40 um, warp is smaller than 40 um, PLTV is larger than 95%, and the production process is suitable for mass production.

The invention discloses a folding silicon-lithium niobate hybrid integrated electro-optic modulator and a preparation method thereof. The folding silicon-lithium niobate hybrid integrated electro-optic modulator comprises a silicon-based input waveguide, a silicon-based optical splitter, a silicon-lithium niobate waveguide coupling structure, a first waveguide arm, a second waveguide arm, a silicon-based optical combiner, a silicon-based output waveguide, a silicon-based waveguide crossing structure, and three electrodes; each of the first waveguide arm and the second waveguide arm comprises asilicon-lithium niobate waveguide coupling structure and more than two lithium niobate waveguides; each of the first waveguide arm and the second waveguide arm further comprises a silicon-based bentwaveguide and a silicon-based cross structure; before the light path turns, the light in the lithium niobate optical waveguide is coupled into the silicon-based optical waveguide from the lithium niobate optical waveguide through the silicon-lithium niobate waveguide coupling structure, the turning of the light path is realized in the silicon-based optical waveguide, and the conversion of the light path in the waveguide is realized through the silicon-based crossing structure connected with the silicon-based bent waveguide. The miniaturization of the modulator can be favorably realized.

The invention discloses a preparation method of a titanium niobate/carbon composite electrode material belonging to the lithium ion battery material technical field. According to the method, ball mill mixing is carried out to titanium dioxide, niobium oxide and carbon source according to a certain proportion; the dried mixture is calcined under the protection of an inert gas, thus obtaining the titanium niobate/carbon composite electrode material. The invention also discloses the titanium niobate/carbon composite electrode material prepared by the preparation method. According to the invention, the conductivity of the material is improved through carbon coverage; meanwhile, a certain inhibiting effect on the particle size increasing phenomenon of the titanium niobate is realized through carbon coverage; the material shows excellent rate capability and cycle performance when being used as the lithium ion battery anode material; in addition, the material and the preparation method of the invention are featured by simple preparation technology, convenient operation and low production cost and are easy in large-scale industrial production.

The invention relates to an optoelectronic integration three-dimensional electric field sensor system, and belongs to the technical field of electric field measurement. The system comprises a laser source, a polarization-maintaining fiber coupler, an input polarization-maintaining optical fiber, a polarizer, a polarization-maintaining tail optical fiber, a sensing head, a polarization beam splitter, an output single mode fiber and a photoreceiver, wherein the output end of the laser source is connected with the input end of the sensing head through the polarization-maintaining fiber coupler, the input polarization-maintaining optical fiber, the polarizer and the polarization-maintaining tail optical fiber in turn, and the output end of the sensing head is connected with the input end of the photoreceiver through the polarization-maintaining tail optical fiber, the polarization beam splitter and the output single mode fiber. The sensing head comprises three parallel through optical waveguides which are formed on the surface of a lithium niobate plate through titanium diffusion; and a vertical dipole antenna and an electrode are laid on two sides of the surface of the first optical waveguide, and a shielding electrode is laid on the surface of the third optical waveguide. The optoelectronic integration three-dimensional electric field sensor system is suitable for detecting three-dimensional electric fields, has the advantages of simple process and high spatial resolution, and can realize close measurement.

An all-optical true random number generator with a Tbps code rate comprises an all-optical true random number entropy source and an all-optical quantizer, wherein the all-optical true random number entropy source adopts an rational harmonic mode-locked Er-doped fiber ring laser, actually a ring-shaped cavity formed by a lithium niobate electro-optic modulator, an optical band pass filter I, an erbium-doped fiber amplifier, an opto-isolator and an optical coupler which are connected through fiber; and the all-optical quantizer is a quantum dot quarter wave phase-shift distributed feedback type laser. The generator provided by the invention solves the problems that the code rate is too low and untunable in the prior art, has a Tbps-level code rate, is in direct compatible with an optical network, and meets the safety requirements of modern high-speed secure communication.

The invention relates to a surface acoustic wave micro-fluidic drive for a chip lab pertaining to the technical field of micro-electro-mechanical system and a manufacture method thereof. The drive of the invention comprises a base, an interdigital transducer and a micro-fluidic channel, wherein the base is a 128 degrees Y-X lithium niobate single crystal, an IDT formed by the intercrossed interdigital transducer is on the base, and the micro-fluidic channel is integrated with the base. The invention uses floating electrode type unidirectional transducer structure design to realize unidirectional driving of the micro fluid, the procedure of the method is: (1) processing of the floating electrode type unidirectional transducer; (2) micro-processing of the micro-fluidic channel; (3) integration of the base and the micro-fluidic channel. The whole processing procedure of the invention can be completely made by means of semiconductor material based micro-manufacture method, having characteristics of no moving micro-parts itself and no damage to the fluid dielectric etc., the processing has advantages of reliable operation, stabilization and long service life.

A hybrid integration process for fabrication of an optical cross-connect switching apparatus. The switching element is based on the deflection of light beam in electro-optic materials by applying electric field across electrodes of an appropriate configuration. The integration process includes fabrication of a substrate (e.g. silicon substrate) with 2D imaging optics from polymeric materials (or silica), fabrication of the light deflecting element, and assembly of the deflecting element on the substrate with imaging optics. The fabrication of the light deflecting element includes fabrication of a LN (lithium niobate) block. The LN block assembled in an optical switching apparatus includes a two-dimensional waveguide formed on a surface of the LN block and an electrode on a surface of the LN block.

There is provided a lithium-transition metal oxide powder with a coating layer containing lithium niobate formed on a part or the whole part of a surface of a lithium-transition metal oxide particle and having a low powder compact resistance, and a positive electrode active material for a lithium ion battery containing the lithium-transition metal oxide powder. Specifically, there is provided the lithium-transition metal oxide powder composed of a lithium-transition metal oxide particle with a part or the whole part of a surface coated with a coating layer containing lithium niobate, wherein a carbon-content is 0.03 mass % or less.

A new form of a solid-state non-volatile memory cell is presented. The solid-state memory cell comprises a series of different layers of ferroelectric materials, semiconductors, ferroelectric semiconductors, metals, and ceramics, and oxides. The memory device stores information in the direction and magnitude of polarization of the ferroelectric layers. Additionally, a method is presented for storing multiple bits of information in a single memory cell by allowing partial polarization of a single ferroelectric layer and stacking of multiple ferroelectric functional units on top of each other. Additionally, a technique for reading and writing said memory cell is presented. Additionally, the memory cell design allows for the formation of Schottky barriers which act to improve functionality and increase resistance. Additionally, a method is presented for depositing textured lithium niobate thin films.

The invention relates to a ferroelectric metal hetero-junction based memristor; wherein the memristor material-ferroelectric lithium niobate is prepared by a pulse laser deposition system; monocrystal LN target material (4) is fixed on a target platform (5) of the pulse laser deposition system, and is placed in a growth chamber (6) of a pulse laser deposition film-making system; the vacuum in the growth chamber is pumped to be below 0.8*10-4Pa, oxygen gas flows in, and the oxygen pressure is from 25 to 35Pa, the substrate temperature is heated from 600-650 DEG; a KrF excimer laser is started, and the deposition time is determined according to monopulse energy; in-situ 500-650 DEG annealing is carried out 20-90min; the film has spontaneous polarization and 180-degree domain boundary; the memristor ferroelectric lithium niobate film is clamped between two metal electrode films to form a memristor unit with a miniature sandwich structure; the device can be applied to a high-density low-energy-consumption nonvolatile resistance random access memory.

The invention relates to a device and method for stabilizing any bias point of an external modulator, wherein the device comprises a laser, a variable optical attenuator, a lithium niobate modulator, an optical coupler, a signal source, a driving amplifier and a feedback control part; the device can be used for collecting a feedback signal and setting a bias voltage via a data acquisition board in the feedback control part so as to stabilize any bias point. The device and the method of the invention solve the problem that an optimal bias point of the modulator is drifted and an output signal is degraded because of changes of factors such as time, environment temperature, laser luminous power, and optical fiber inserting and coupling loss. The device and the method can be applied in the optical communication field, especially high-speed long distance communication in the optical communication field.

A silicon-insulator-silicon capacitive (SISCAP) optical modulator is configured to provide analog operation for applications which previously required the use of relatively large, power-consuming and expensive lithium niobate devices. An MZI-based SISCAP modulator (preferably a balanced arrangement with a SISCAP device on each arm) is responsive to an incoming high frequency electrical signal and is biased in a region where the capacitance of the device is essentially constant and the transform function of the MZI is linear.

An optical modulator includes a single-crystal substrate, a lithium niobate film formed on a main surface of the single-crystal substrate, the lithium niobate film being an epitaxial film and having a ridge, a buffer layer formed on the ridge, a first electrode formed on the buffer layer, and a second electrode separated from the first electrode, the second electrode being in contact with the lithium niobate film.

The invention discloses a lithium-niobate-based hybrid integration fiber-optic gyroscope optical chip which comprises a lithium niobate waveguide chip, a light source and a signal detector. The lithium niobate waveguide chip comprises a first Y branch waveguide, a second Y branch waveguide, three 90-degree arc waveguides, a conical waveguide and a straight waveguide which are communicated with one another. The wide end of the conical waveguide serves as a light input port of the optical chip. The light source is right opposite to the light input port. One end of the straight waveguide serves as a signal output port of the optical chip. The light sensitive face of the signal detector is right opposite to the signal output port. A preparation process of the optical chip mainly adopts a photo-etching method and is obtained through the combination of the dry-method etching technology and the titanium-diffusion and annealing proton exchange technology; the integrated chip replaces an optical device separately assembled in a traditional fiber-optic gyroscope, the light source, the detector, a coupler and a modulator are integrated on a lithium niobate substrate, the integrity of a fiber-optic gyroscope optical system is improved, and therefore the reliability and environment adaptability of the fiber-optic gyroscope are improved.

The invention discloses a lithium niobate wafer grinding device with a grinding pressure adjusting device and a grinding method. The grinding device comprises a three-dimensional space positioning device, a beam type force sensor and a grinding and clamping mechanism. The three-dimensional space positioning device is provided with the grinding and clamping mechanism through a force sensor, and two lithium niobate wafers clamped by the grinding and clamping mechanism are positioned at any point in the space. A clamping mechanism of the grinding and clamping mechanism is installed on a sliding block in the grinding pressure adjusting device in a sliding manner. A calibrated adjusting screw with a read head is adopted in the grinding pressure adjusting device, and adjustment of the pressure between the lithium niobate wafers and a grinding table is achieved in the grinding process. During grinding, the distances between contact points of the two lithium niobate wafers and a grinding machine and a main shaft of the grinding machine need to be equal. The lithium niobate wafer grinding device has the beneficial effects that the calibrated adjusting screw with the read head is adopted, and adjustment of the grinding pressure is visual and reliable; and during grinding, a positioning manner of the two lithium niobate wafers is adopted, and the grinding mass of the two lithium niobate wafers is the same.

The invention belongs to the technical field of fiber optic gyroscopes and especially relates to a double-coupling optical fiber ring resonator coherent effect-based resonant fiber optic gyroscope. The double-coupling optical fiber ring resonator coherent effect-based resonant fiber optic gyroscope solves the problem that the traditional resonant fiber optic gyroscope has low sensitivity and does not satisfy high sensitivity requirements of commercial airplanes, spatial orientation and navigation. The double-coupling optical fiber ring resonator coherent effect-based resonant fiber optic gyroscope comprises a laser, a polarization controller, a lithium niobate phase modulator, a first optical fiber coupler, a first optical fiber ring resonator, a second optical fiber coupler, a second optical fiber ring resonator, a third optical fiber coupler, a detector, and a signal processing and feedback system. The two optical fiber ring resonators prepared respectively from two optical fibers having different length are coupled and produce coherent effects and through measurement of a change of coherent resonant frequency of the two optical fiber ring resonators, a rate of angular motion is obtained. Compared with the traditional resonant fiber optic gyroscope having the same resonant optical fiber length, the double-coupling optical fiber ring resonator coherent effect-based resonant fiber optic gyroscope has sensitivity improved by dozens of times.