127 results about "Magneto-optic effect" patented technology

An optical waveguide isolator for use in an optical communication system is disclosed. The optical waveguide isolator comprises a semiconductive light amplifier structure including a semiconductor substrate of first conductivity type having a surface of a layer to be formed thereon, a first cladding layer of first conductivity type formed on the substrate, an active layer formed on the first cladding layer, a second cladding layer of the second conductivity type opposite to first conductivity type, formed on active layer, a first electrode formed on the surface of the semiconductor substrate opposite to the surface to be formed as a layer, and a second electrode formed on the second cladding layer; the first and the second cladding layers and the active layer form an optical waveguide in which the light wave propagates. The semiconductive light amplifier structure further comprises a light absorptive magnetic material layer having light absorption function for the light wave propagating through the optical waveguide. The magnetic material layer is magnetized so as to have the magnetic-field component in the direction which corresponds to the direction where a magnetic vector of the light wave vibrates, the waveguide structure body has a nonreciprocity optical characteristic that effective refractive index changes into the light wave to which the optical waveguide is propagated according to the magnet-optical effect of the light absorptive magnetic material layer according to the direction of propagation, by the effective refractive index change in the nonreciprocity, the attenuation of the first light wave that the optical waveguide is propagated in the first direction caused when the said waveguide is propagated, becomes small more than the attenuation of the second light wave propagated in the second direction opposite to the first direction caused when the said waveguide is propagated.

The invention discloses an optical current sensor based on the Faraday magneto-optic effect. The optical current sensor comprises a laser generator which is used to generate polarized laser of a set wavelength, an integrated probe which comprises a magneto-optical medium, a photodetector which is used to convert an optical signal into an electrical signal, and a data analyzing and processing device which filters out noise through the combination of hardware filtering and software filtering to acquire a good response effect. A polarizer and an analyzer are arranged on two ends of the magneto-optical medium respectively, and are insulatedly packaged on both ends of the magneto-optical medium respectively. The laser generator and the polarizer are connected through an optical fiber path, andthe photodetector and the analyzer are connected through an optical fiber path. The invention further discloses a current measurement method of the optical current sensor based on the Faraday magneto-optic effect.

An integrated fiber optic switch based on the magneto-optic effect of magnetic materials suitable for optical fiber networks is presented. The switch is based on the Faraday Effect exhibited by magneto-optic materials. The all-fiber magneto-optic switch has a beam splitter at the input that splits an incoming signal into orthogonal polarized paths. Each path has at least one magneto-optic Faraday rotator (MOFR) controlled by a field. When the field is present, the polarization of the optical beam changes, thereby turning the switch on or off. A beam coupler couples the orthogonal polarized paths at the output of the all-fiber magneto-optic switch. The switch is constructed in the Mach-Zehnder configuration, utilizing two 3 dB couplers, isolators and MOFRs fabricated on silicon-on-insulator.

The invention discloses an optical fiber current sensing measurement system based on optical fiber magneto-optical effect, comprising a light source, a first transmission optical fiber, an optical fiber sensor head, a second transmission optical fiber and a photoelectric conversion and signal processing unit; the optical fiber sensor head comprises a polarization beam splitter, a Faraday rotator and an annealing optical fiber ring with a holophote; the light source transmits the light to the optical fiber sensor head by the first transmission optical fiber; wherein, the annealing optical fiber ring anneals under high temperature so as to eliminate dual-refraction in the optical fiber and improve the stability of the sensor head under the change of environmental temperature. The photoelectric conversion and signal processing unit is connected with the sensor head by the second transmission optical fiber.

The invention provides an optical analog-to-digital converter based on polarization modulation, belonging to the field of photoelectric technology, and relates to a photoelectric signal processing and optical analog-to-digital converter. N-path current modulation signals uniformly divided by a sampling analog current signal are respectively input to a magnetic induction coil by an amplifying circuit; pulsed light emitted by a laser is polarized into a linearly polarized light by a polarizer, and the linearly polarized light is divided into N light path signals by a beam splitter, and the N light path signals are respectively input to N photoelectric branch circuits; the optical signal of each photoelectric branch circuit firstly passes through magneto optic effect material in the magnetic induction coil, and then is analyzed by an analyzer into an optical signal which is converted into an electrical signal by a photoelectric detector, the electrical signal is amplified by an amplifier and is input to the corresponding comparer to carry out threshold value judgment, and a digital signal is finally output by the comparer. The converter can realize the output of the digital signal with the traditional binary code and Gray code, and has the advantages of rapid sampling speed, more effective number bits, no restriction of the binary code and the Gray code, simple structure and low cost.

The present invention relates to a magnetooptical device utilizing a magnetooptical effect provided by using a magnetic garnet material, and provides a magnetic garnet material which is less likely to crack during the growth and lapping of the single crystal film. It is an object of the invention to provide a magnetooptical device which defines a Faraday rotation angle theta expressed by 44 deg.<=theta<=46 deg. when light having a wavelength lambd (1570 nm<=lambd<=1620 nm) impinges thereupon, in order to permit the suppression of and which is less likely to crack during processing to allow any reduction of yield. A magnetic garnet material expressed by a general formula: BiaM13-aFe5-bM2bO12 is used. M1 is at least one kind of element that is selected from among Y, La, Eu, Gd, Ho, Yb, Lu and Pb; M2 is at least one kind of element that is selected from among Ga, Al, Ti, Ge, Si and Pt; and a and b satisfy 1.0<=a<=1.5 and 0<=b<=0.5, respectively.

The invention discloses a differential detection device for a coherent layout imprisoned magneto-optic effect. The differential detection device comprises a bias coupler, a laser, a solenoid, alkali metal atomic vapor bubbles, a polarization beam splitting crystal, a photoelectric cell and a second photoelectric cell. The invention also discloses a differential detection method for the coherent layout imprisoned magneto-optic effect. According to the method, differential detection is performed on a laser signal obtained after linearly polarized light and atoms are mutually interacted in a magnetic field; through the scheme, common-mode noises which are associated with laser amplitude noises and frequency noises can be inhibited, so that the signal-to-noise ratio of the signal is improved; therefore, the stability of the output frequency of a coherent layout imprisoned atomic clock is improved. A passive coherent layout imprisoned atomic clock realized by adopting the scheme has the advantages of simple structure, low cost, small size and the like, and is suitable for realizing small and micro atomic clocks. The invention also discloses the differential detection method for the coherent layout imprisoned magneto-optic effect.

A micro-fluidic faraday rotation reinforcer relates to a novel micro-fluidic faraday rotation reinforcer structure. The rotation reinforcer (8) consists of a rotation reflection cavity (7) and a polarized beam splitter prism (3) outside the rotation reflection cavity (7); wherein the rotation reflection cavity (7) consists of a partially reflecting mirror (4) and a total reflecting mirror (5) which are parallelly arranged and a magneto-optic medium (6) between the partially reflecting mirror (4) and the total reflector (5); when the light path passing through a sample is constant, a magnetic field (9) is added along the light propagation direction; according to the nonreciprocity of magnetooptical effect, the rotation reinforcer (8) is used for improving measuring sensitivity to micro rotation angle; and a light source (1) is arranged beside the polarized beam splitter prism (3). According to the nonreciprocity of Faraday magnetooptical effect, when the beam passes through the sample medium back and forth for a plurality of times, the rotation angle can be multiplied. The micro-fluidic reinforcer designed by the invention has the advantages of simple structure, easy manufacture and convenient integration.

The invention provides an all-optical-fiber current transformer and a current measuring method thereof. The all-optical-fiber current transformer is mainly formed by three parts: a sensing unit, a signal processing unit, and a merging unit. The sensing unit employs the Faraday magneto-optic effect principle and used for inducing current of a measured conductor, and generating light intensity signals carrying data information of the Faraday rotation angle. The signal processing unit mainly completes input of optical singles of the sensing unit, analysis of the output optical signals, digitalization processing, and temperature compensation etc., and performs output according to a prescribed synchronous serial mode. The merging unit completes synchronization, switching or parallel logic of information of the signal processing unit, and transmits the information to an electrical measuring instrument and a relay protection device.

The invention discloses a crystal current sensor based on composite optical vortex. A laser emission unit is used to emit a linear polarization state fundamental mode Gaussian beam, and a composite beam generating unit is used to divide the linear polarization state fundamental mode Gaussian beam into two beams, and is used to modulate the two beams into optical vortex beams, which are combined together, and are converted into circular polarization type composite optical vortex beams. A crystal sensing unit is used to transmit the composite optical vortex beams into a crystal along the optical axis of the crystal, and is used to apply the current to the crystal to generate a magnetic field along the direction of the optical axis of the crystal. A detection unit is used to detect the light intensity distributions of the composite optical vortex beams before and after the application of the magnetic field, and the deflection of the composite optical vortex beams occurs, and the current is calculated by calculating the deflection degree, and therefore a current sensing function is realized. The circular polarization state characteristic of the optical vortex during a transmission process is maintained, and the change of the beam polarization state by using Faraday magneto-optic effect can be directly displayed in composite spots, and therefore a problem of reduction of sensitivity of an optical fiber current sensor caused by linear birefringence is effectively solved.

A spatial light modulator includes: a magnetic layer that is made of a magneto-optic material and includes a plurality of pixels in each of which a magnetization direction is independently set and each of which has a function of causing a rotation of a polarization direction of incident light depending on the magnetization direction by a magneto-optic effect; a plurality of first conductor layers and a plurality of second conductor layers arranged to intersect with each other at positions corresponding to the individual pixels, through which currents for generating magnetic fields to set the magnetization directions in the individual pixels are passed; and a plurality of dielectric layers for enhancing the function of the pixels. A polarization direction of light incident on the spatial light modulator is rotated depending on the magnetization direction of each pixel.

The invention discloses a multiferroic liquid and a preparation method of the multiferroic liquid. The multiferroic liquid of the invention is obtained via the following steps: uniformly mixing a base fluid and a surface active agent as a mixed liquid; then adding ferroelectric nano-particles and magnetic nano-particles in the mixed liquid, shaking the mixture and putting the mixture in a sealed container, and putting the container in a shaking table to shake for more than half an hour to make nano-particles evenly dispersed in the mixed liquid, thereby obtaining a stable suspension liquid, namely the multiferroic liquid. The multiferroic liquid of the invention not only has magnetism and ferroelectricity, but also has fluidity, and is very sensitive to a magnetic field and an electric field. Compared with solid ferroelectric material, the multiferroic liquid of the invention has smaller coercive force, and the particles are easy to rotate under the electric field or the magnetic field. The multiferroic liquid of the invention also has a magneto-optic effect and a refraction effect, which are not possessed by the solid multiferroic material. The invention presents the multiferroic liquid and the preparation method of the multiferroic liquid for the first time so as to develop a new direction for researching the multiferroic material.

An all-fiber isolator as an optical isolator comprises: an optical fiber acting as an optical light guide for propagating incident light; and a Faraday rotator for rotating by 45° a plane of polarization polarized by the polarizer. The all-fiber isolator exhibits a magneto-optic effect enough to be used as an optical isolator at a visible light wavelength by including quantum dots in a core layer and/or an internal cladding layer of the optical fiber.

The invention discloses a measuring method and a measuring device of non-contact electrostatic spraying charge-to-mass ratios, and the measuring method and the measuring device are particularly suitable for calculation of charge-to-mass ratios of charged fogdrops in induction charging and corona charging. The measuring device comprises a laser transmitter (1), an electrostatic sprayer (4), a polarizer (2), a reflector (3), a reflector (3'), a magneto-optical element (6), an analyzer (7), a composite polarized light prism (8), an optical-electrical converter (9), a differential amplifier (10), wires (11) and an oscilloscope (12), wherein the light emitted by the generating laser (1) is a sheet light source. The diameter of the magneto-optical element is D, the distance between the electrostatic sprayer (4) and the magneto-optical element (6) is H, the mist spraying angle of the electrostatic sprayer is theta, and D, H and theta meet the relation that D=2H*tan(theta/2). Current values of all fogdrops on a charged fogdrop group section can be calculated without contact by the utilization of the Faraday magneto-optical effect and the Ampere circuital theorem through the measuring device, then the current values are divided by mass flow rates of a charged foglet group, and the charge-to-mass ratios can be calculated.

The invention relates to the laser field, in particular to an intracavity frequency doubling laser. The invention includes that a modulator which can adjust fundamental wave light loss in high speed and small amplitude, such as a modulator made by adopting electro optical effect, magneto optic effect, piezoelectric effect or etalon effect, is added into the intracavity frequency doubling laser ofa continuous pump. The characteristic that intracavity frequency doubling laser output power is highly sensitive to intracavity fundamental wave light loss is utilized to realize high speed modulationof frequency doubling laser output power. The invention is especially applicable to high speed modulation of various laser sources in laser display. The invention utilizes new modulation theory and the characteristic that intracavity frequency doubling laser output power is highly sensitive to intracavity fundamental wave light loss to realize high speed modulation of frequency doubling laser output power. The defects of the prior art that modulation range is limited and structure is relatively complex are overcome, and wide frequency range regulation from low frequency to high frequency of the intracavity frequency doubling output light can be realized simply and conveniently.

The invention discloses an optical voltage transformer comprising a voltage-current converter, an optical low-current sensor, and a protection gap. The voltage-current converter is implemented by a high-voltage capacitor and converts primary high voltage into low current. The optical low-current sensor is implemented by a magneto-optic glass optical current transformer and is formed by a magneto-optic glass primary sensor, a transmission optical cable, and an acquisition unit. The magneto-optic glass primary sensor is a magneto-optic glass sensing probe disposed in a solenoid and induces the low current output by the voltage-current converter by means of a Faraday magneto-optic effect. The transmission optical cable is connected with the magneto-optic glass primary sensor and the acquisition unit. The acquisition unit is arranged in a master control chamber or an outdoor cabinet, demodulates a low-current signal induced by a magneto-optic glass optical current transformer optical path system, and outputs a digital signal, indicative of primary voltage, to be used by a relay protection device and a metering device.

A target material for magneto-optical record (optical disk or magneto-optical disk) is based on the principle that the light- or medium-weight rare-earth elements have high saturation magnetization intensity, magnetocrystalline anisotropy and magneto-optical effect. It is prepared through magnetic suspension smelting of FeCo alloy as basic target alloy, linearly cutting the pure terbium and light-weight rare-earth element to obtain sectorial or circular sheets, symmetrically inlaying them on said basic target. Its advantages are high uniformity, low cost and high efficiency.

A delay interferometer includes first and second optical paths into which incident signal light is split, a first converter including one or more conversion parts to convert the signal light on the first optical path into circularly polarized light and to convert the circularly polarized light into linearly polarized signal light, a phase adjuster to shift an optical phase of the circularly polarized light through a magneto-optic effect, and a second converter to convert a polarization state of the signal light on the second optical path into substantially the same polarization state as a polarization state of the linearly polarized signal light.

The invention discloses a device and method for measuring high nonlinear optical fiber Verdet constants, and belongs to the technical field of optical fiber communication and optical fiber sensing, in particular to a novel photon information processing technology based on optical fiber nonlinear effects and magneto-optic effects. According to the device and method for measuring the high nonlinear optical fiber Verdet constants, the Verdet constants of optical fibers are calculated by using the nonlinear coefficients of the optical fibers, optical pulses are generated by using a mode locking optical fiber laser, the optical pulses pass through a polarization controller, an erbium-doped optical fiber amplifier, a band-pass filter and an attenuator in sequence to obtain proper high power optical pulse signals, the initial root-mean-square spectrum width of the optical pulses before being input in the optical fibers and the maximum root-mean-square spectrum width of the optical pulses after passing through the optical fiber are measured by using a spectrograph, and the nonlinear coefficients of the optical fibers are calculated; a magnetic field is further applied to the optical fibers, the nonlinear coefficients of the optical fiber after the magnetic field is applied are calculated by adopting the same method, and the Verdet constants are calculated through the two times of the nonlinear coefficients of the optical fibers. Therefore, the device and the method for measuring the high nonlinear optical fiber Verdet constants have the advantages that the Verdet constants of the optical fibers are measured accurately and fast, and the operation is easy and convenient to carry out.