1586 results about "Optical isolator" patented technology

A non-optical isolator having a driver circuit for providing an input signal to one or more first passive components which are coupled across a galvanic isolation barrier to one or more corresponding second passive components, and an output circuit that converts the signal from the second passive components to an output signal corresponding to the input signal. The entire structure may be formed monolithically as an integrated circuit on one or two die substrates, for low cost, small size, and low power consumption. The passive components may be coils or capacitor plates, for example. When the first and second passive components are capacitor plates, a Faraday shield may be provided between them, with the first and second passive components being referenced to separate grounds and the Faraday shield referenced to the same ground as the second passive components.

A direct access arrangement (DAA) device is provided that is configured to interface a security alarm modem with a phone network. The DAA device comprises a receive optical isolator (OI) module having a receive input side and a receive output side. The receive input side includes a receive input line configured to receive a remote signal from the phone network. The receive output side includes a receive output line configured to convey the remote signal to a security alarm modem. First and second transmit OI modules are provided that each have a transmit input side and a transmit output side. The transmit input sides have transmit input lines joined in parallel with one another and configured to receive transmit signals from the security alarm modem. The transmit output sides have transmit output lines joined in parallel with one another and configured to convey the transmit signals to the phone network. An impedance matching module is joined to the transmit output sides of the first and second transmit OI modules and configured to provide impedance matching with the phone network. Optionally, the transmit output lines from the first and second transmit OI modules may be joined in parallel with the receive input line. The first and second transmit OI modules may include first and second LEDs, respectively, that draw substantially equal diode currents. The receive and first and second transmit OI modules may each have an associated diode current, where the receive module is interconnected with the first and second transmit OI modules such that the diode current collectively utilized by the first and second transmit OI modules changes by an amount that is substantially equal in amplitude, but opposite in polarity, to the diode current utilized by the receive OI module.

An optical amplifier having a two-stage construction using an erbium doped fiber (EDF) as a gain medium. The erbium dopant concentration is 1000 ppm, and the unsaturated absorption coefficient of the signal beam at 1550 nm is 1 dB / m. The length of the EDF 14-8 is 10 m, and the length of the EDF 14-12 is 70 m. The excitation light sources 14-6 and 14-10 are semiconductor lasers of 1.53 mum, and the excitation light power is 100 mW. Multiplexers 14-7 and 14-11 are inductive multi-layer film filters, and the gain equalizer 14-4 is a Fourier filter. The peak loss of the Fourier filter is 17 dB. The gain of the EDF 14-8 is 25 dB, and the gain of the EDF 14-12 is 15 dB. Two optical isolators are installed on a pre-stage amplifier, and one on a post-stage amplifier in order to prevent laser oscillation.

A method for fabricating an integrated optical isolator includes depositing a wire grid material on a magneto-optical substrate and depositing a resist film on the wire grid material. The method further includes bringing a mold with a wire grid pattern on contact with the resist film and compressing the mold and resist film together so as to emboss the wire grid pattern in the resist film. The method further includes transferring the wire grid pattern in the resist film to the wire grid material on the magneto-optical substrate by etching.

PCT No. PCT / RU97 / 00278 Sec. 371 Date Jul. 9, 1998 Sec. 102(e) Date Jul. 9, 1998 PCT Filed Sep. 3, 1997 PCT Pub. No. WO98 / 28643 PCT Pub. Date Jul. 2, 1998The invention relates to fiber optics and can be employed in fiber radiation collimators, optical waveguide couplers, spectral filters, optical isolators, long-period gratings, dispersion compensators, cascade mode field diameter conversion fibers on simulated Raman effect, physical value sensors, radiation suppression units for predetermined wavelengths, and for smoothing the gain spectrum in erbium fiber amplifiers. The invention facilitates fabrication of optical waveguides and apparatuses based on them. To produce preforms for optical waveguides (1) by a plasma chemical vapor deposition method, molecular gaseous agents, fed to a substrate tube (24), are mixed so that less than five atoms of oxygen fall on every atom of silicon and more than one atom of nitrogen falls on every 1000 atoms of oxygen. The refractive index is locally changed by heating a length of an optical waveguide (1). This causes a local thermal diffusion of elements contained in a core (3) into a cladding (2), or vice versa. The length of the optical waveguide (1) is heated by current of an electric arc (10) or by radiation (16) of an infrared laser (15). The core (3) is doped with nitrogen at concentration from 0.01 at. % to 5 at. %. In the mode field diameter conversion fiber, a diameter of the core (3) changes along the length of the optical waveguide (1), increasing towards its end (4).

The invention discloses a method for measuring high reflectivity based on self-mixing effect of semiconductor laser which belongs to the technical field of measuring optical elements parameter. The present cavity ringdown technique for determining high reflectivity by measuring ringdown time, using the self-mixing effect of semiconductor laser, improves laser power to coupling efficiency of ringdown cavity by controlling back feedback optical intensity of continuous wave semiconductor laser, greatly improves the signal-noise ratio of cavity outputting signal, thereby improving measuring precision and measuring range of high reflectivity. The methods for controlling back feedback optical intensity which can make the cavity output signal reach the maximum include: inserting a linear polarizer, an attenuation plate, an optical isolator or a variable aperture between the semiconductor laser and the first cavity mirror, or adjusting the pitching of the first cavity mirror, or changing the distance of the laser and the first cavity mirror.

The optical interrogation system comprises an optical sensor and an optical isolator that filters parasitic reflections introduced by the optical sensor.

A patient temperature repeating system and a method of repeating patient temperature information from a resistive-type patient temperature sensor allow one or more medical instruments to utilize a single patient temperature sensor. In one embodiment, the patient temperature repeating system (10) includes input and output connectors (12, 14), a microprocessor (20), optical isolators (22), a coarse digital potentiometer (24) in parallel with a fine digital potentiometer (26), a current sense resistor (28), amplifiers (30A, 30B), analog-to-digital converters (32A, 32B), a filter (34), fuses (36), a non-volatile memory device (38), and a relay (40). In operation, the microprocessor (20) reads the resistance level of a resistive-type patient temperature sensor (16) connected to the input connector (12) and provides the appropriate control signals through the optical isolators (22) to the coarse and fine digital potentiometers (24, 26) in order to set the resistance seen by a medical device (18) connected to the output connector (14) to match that of the patient temperature sensor (16).

A device and a method for ultrafast picosecond pulse laser machining of a super-hydrophobicity micro-structure surface belong to the field of preparation of functional micro-structure surfaces, and aim to solve the problems of high investment and low output of an existing machining process and existing machining technology for functional elements. The device comprises an ultrafast picosecond pulse laser source, an optical isolator, five reflectors, a rotary liquid crystal polarizing film, a polarization beam splitter, two beam collectors, a half wave plate, a focusing lens, frequency-doubling generator LBO (lithium triborate) crystal, a dichroic mirror, a light control device, a beam profile curvometer, a beam amplifying component Kepler beam expander, a focusing machining lens, a machining platform, a microscopy imaging CCD (charge coupled device) component and a control system. The method includes the stepsof: fixing a steel workpiece onto a surface driven by a Z-directional guide rail of the machining platform; adjusting a light path; detecting the surface of the workpiece by a probe; and driving the workpiece to move by means of movement of an X-directional guide rail and a Y-directional guide rail of the machining platform. The device and the method are used for preparing the super-hydrophobicity micro-structure surface.

A polarization element and a polarization-sensitive optical isolator are integrated to form an integrated VOA. A preferred embodiment uses a liquid crystal cell as the polarization element to which is attached an optical isolator core of a first polarizer, Faraday rotator, and second polarizer. Voltage on the liquid crystal cell electrodes controls the amount of polarized light from the liquid crystal cell passing through the first polarizer and light in the opposite direction is blocked. The integrated VOA can be mounted within a laser device package so that the power of the source laser diode on the output fiber can be controlled and yet the laser diode is protected from light undesirably entering laser device package through the output fiber.

An integrated circuit device includes an insulating body provided with a number of electrically conductive leads and having a surface provided with a red LED aperture, an IR LED aperture and a photodetector aperture. The insulating body also includes an optical isolator optically separating the photodetector aperture from the red LED aperture and the IR LED aperture. A red LED is aligned with the red LED aperture, an IR LED is aligned with the IR LED aperture, and a photodetector is aligned with the photodetector aperture.

Methods and apparatus for optimizing feedback suppression of optical isolators when used with variable wavelength light sources. The methods comprise positioning an optical isolator in a light beam, and adjusting feedback suppression by the optical isolator according to wavelength of the light beam. Adjusting the feedback suppression may comprise adjusting temperature of the optical isolator or a non-reciprocal rotator associated with the isolator.

The invention discloses a battery management system of an electric vehicle, which comprises a primary vehicle-body system, a main controller and a battery pack, wherein, the battery pack is formed by more than two batter modules connected in series, the batter modules are formed by connecting more than two single cells in series, each battery module is provided with a battery collecting module, the battery pack is respectively connected with a complete vehicle power system through a discharging relay and a charging relay, the main controller is connected with a previous complete vehicle system through a first optical isolator, and the battery collecting module is connected with the main controller through a second optical isolator. The battery management system has the advantages that: as the battery management system is composed of the main controller (BMU) and the next battery collecting module (LECU), the composition of the system structure is simplified through the main controller and the next battery collecting module, the cost of the hardware of the system can be reduced, and simultaneously, the reliability of the management system can be greatly enhanced.

A fiber laser gas detection system with a double wavelength combination using reference cavity compensation is provided. The system comprises an optical fiber laser respectively emitting beams having a first and second wavelengths, which consists of a laser diode pump source, a first wavelength division multiplexer, an active optical fiber, a first fiber bragg grating and a second fiber bragg grating connected successively; an optical isolator; a coupler for dividing the beams according to power ratio, the divided beams is introduced into a reference gas chamber and a detecting gas chamber respectively; a second wavelength division multiplexer connecting the reference room and a third wavelength division multiplexer connecting the detecting gas chamber; a first, a second, a third and a fourth photoelectric detector; a feedback control unit, receiving the first to fourth light intensity signals and adjusting the fiber laser using the comparison results as a feedback signal.

An optical transmitter includes an optical bench in one embodiment. A window frame is mounted to a mounting block having a groove to form the optical bench. Optic and electro-optic components of the optical transmitter are mounted to the optical bench. The window frame includes a plurality of openings for mounting one or more ball lenses, an optical isolator, and a semiconductor laser. The semiconductor laser chip is used to generate light signals for optical communication over an optical fiber. The one or more ball lenses may be mounted into ball lens openings of the window frame and extend into the groove of the mounting block. One of the ball lenses maybe used to focus light signals between an optical fiber and the optical transmitter. Another one of the ball lenses may be used to collimate the light output from the semiconductor laser. In another embodiment, an optical receiver includes the optical bench. In yet another embodiment, an optical transceiver includes the optical bench.

The invention relates to a distributed optical fiber sensing system, and in particular relates to a chaos Brillouin optical coherence domain analysis distributed optical fiber sensing device and method. According to the invention, the problems of unavailable spatial resolution and sensing distance combination, severely limited sensing distance and low spatial resolution of the existing distributed optical fiber sensing system are solved. The chaos Brillouin optical coherence domain analysis distributed optical fiber sensing device comprises a wide spectrum chaos semiconductor laser, a 1*2 optical fiber coupler, an optical scrambler, an optical isolator, a first optical amplifier, a variable optical delay line, a second optical amplifier, an optical circulator, a sensing optical fiber, a tunable optical filter, a broadband gain photodetector, a data acquisition device, a signal processing device and a display device. The device and the method, which are provided by the invention, are applicable to the field of distributed optical fiber sensing.

An optical amplifier includes an erbium doped fiber of which at least one of a core part and a clad part is doped with erbium, excitation light sources or exciting the optical fiber, optical means for inputting excitation light from the excitation light source and signal light to the Er-doped fiber, and an optical isolator. The erbium doped fiber is a 1.58 mum band optical fiber having an equivalent fiber length as a product of a fiber length (m) and an erbium doping concentration (ppm by weight), which length provides a signal gain obtained at a wavelength of the excitation light source used for excitation of the erbium doped fiber of more than a predetermined practical reference value.

The invention relates to a four-degree-of-freedom optical measuring head based on semiconductor laser components. Including the probe mechanism and the target mirror mechanism; the probe mechanism includes semiconductor lasers, four-quadrant photodetectors, two-dimensional PSD position sensitive detectors, optical isolators and plano-convex lenses; the target mirror mechanism includes half-transparent mirrors and corner cubes; When used for measurement, the measuring head mechanism is fixed on the workbench, and the target mirror mechanism is fixed on the main shaft of the power head. The light beam emitted by the semiconductor laser is divided into two beams after passing through the polarizing beam splitter. One of the beams is incident on the half-mirror, and 50% of the light will pass through the half-mirror and enter the corner-cube prism, and then pass through the corner-cube prism. Reflected onto the four-quadrant detector, it is used as a reference beam for measuring two-dimensional linear displacement X, Y. The other half of the beam incident on the half-mirror will return along the original path and enter the beam splitter again, be reflected vertically to the plano-convex lens, and then be collimated and focused on the two-dimensional PSD by the plano-convex lens, which is used as the angle error (pitch angle , deflection angle) of the reference beam.

A magnetic garnet single crystal film formation substrate 2 for growing a thick magnetic garnet single crystal film, wherein crystal defects, warps, cracks and flaking, etc. are not caused, by liquid phase epitaxial growth is provided. The substrate 2 comprises a base substrate 10 composed of a garnet-based single crystal being unstable with a flux used for the liquid phase epitaxial growth; a buffer layer 11a composed of a garnet-based single crystal thin film formed on a crystal growing surface 10a of said base substrate 10 and being stable with said flux; and a protective layer 11b formed at least on side surfaces 10b of said base substrate 10 crossing with said crystal growing surface of said base substrate 10 and being stable with said flux. By using the substrate, a high quality magnetic garnet single crystal film can be produced. The magnetic garnet single crystal film is used as an optical element, such as a Faraday element, used for an optical isolator, optical circulator and magneto-optical sensor, etc.

The invention discloses a sensing signal detecting device and a sensing signal detecting method based on a fiber Brillouin ring laser. The device comprises a narrow linewidth DFB (distributed feedback) laser, three optical fiber couplers, a pulse modulator, two erbium-doped fiber amplifiers, two optical fiber circulators, two single-mode fibers, an optical isolator, a polarization controller and a photoelectric detector, wherein the fiber Brillouin ring laser is composed of the second optical fiber circulator, the second single mode fiber, the optical isolator, the second optical fiber coupler and the polarization controller. Light emitted from the laser is divided into two beams of light via the optical fiber couplers, wherein the probe light is modulated into pulsed light which enters into sensing optical fiber after passing through the erbium-doped fiber amplifiers to ensure that back spontaneous Brillouin scattered signals are generated; the reference light passes through the center frequency of the fiber Brillouin ring laser to ensure that a Brillouin frequency shift is generated; and the coherent detection is carried out on the two Brillouin scattered signals which are scattered back to ensure that the advantages of rapid high-accuracy detection and simple structure are realized by utilizing low-cost devices.

An optical isolator for coupling light from a first waveguide to a second waveguide is disclosed. The optical isolator utilizes a resonator coupled to the first and second optical waveguides. The resonator has a resonance at λ for light traveling from the first optical waveguide to the second optical waveguide; however, the resonator does not have a resonance at λ for light traveling from the second waveguide to the first waveguide. The resonator can use a layer of ferromagnetic material in an applied magnetic field. The magnetic field within the ferromagnetic material varies in strength and / or direction over the layer of ferromagnetic material. The magnetic field can be generated by an external magnetic field that varies over the layer of ferromagnetic material. Alternatively, the resonator can include a layer of ferromagnetic metal that overlies a portion of the layer of ferromagnetic material and a constant external magnetic field.

A Class D switching audio amplifier incorporating four state modulation, input-to-output drive and feedback signal isolation, dual topology output filtration, and a low inductance board layout. The four state modulation results in a common mode voltage in the absence of audio. The input-to-output isolation of drive and feedback signals allows for elimination of large power transformers in applications without user-accessible outputs. Such isolation may make use of optical isolators. The output filter includes common mode and differential topology filter stages. The low inductance board layout treats the amplifier and power supply boards as modules, and utilizes both sides of the amplifier board in order to minimize trace length.

An optical modulation apparatus is provided which implements a stable amplifying function by reducing the effect of reflected light rays form end faces of a bidirectional optical amplifier by imposing a numerical limitation on the relationship between the gain of the bidirectional optical amplifier and the loss of the optical modulator, or by inserting a polarization rotation section in a reflection type optical modulator including the bidirectional optical amplifier or in a multi-wavelength collective optical modulation system combining the multiple optical modulators. An optical modulation apparatus is provided which implements a stable amplifying function and cost reduction by reducing the effect of reflected light rays by interposing optical isolators at every alternate SOAs in a transmission-type optical modulation apparatus including a plurality of semiconductor optical amplifiers (SOAs) connected in a multistage fashion.

An integrated isolator array is provided having a plurality of waveguides fabricated in a planar optical substrate, each waveguide having input and output sections. An isolator subassembly is received within a transverse trench formed in the substrate between the input and output sections such that it intersects the optical paths of the waveguides. The isolator subassembly, which may consist of layers of Faraday rotator material sandwiched between layers of birefringent crystal material, permits the forward passage of light from the input sections to the output sections of the waveguides while preventing the backward passage of light from the output to the input sections. Each waveguide input section is preferably adapted with a mode-expanding input taper to collimate light propagating through the waveguide. Similarly, each output section is preferably adapted with a mode-reducing output taper to reduce the mode size of forward-traveling light to match that of an output fiber, as well as to collimate light traveling backward within the output section.

The present invention relates to a laser processing apparatus which can be miniaturized and has a structure for achieving effective protection of the fiber laser light source. The laser processing apparatus comprises a fiber laser light source, a collimator, a spatial filter, an optical isolator, and a condenser lens. The optical isolator emits laser light from the collimator laser light in parallel to the direction of incidence of the laser light, and emits return light from the condenser lens at a predetermined angle with regard to the direction of incidence of the return light. The spatial filter comprises a pair of condenser lenses disposed such that the focal point is formed therebetween, and a pinhole mask disposed such that the pinhole is located at the focal point. At least, a part of the return light emitted from the optical isolator is blocked by the pinhole mask of the spatial filter.

The present invention provides a bi-directional optical module with an optical isolator to prevent stray light from entering the laser diode (LD). The module includes a distributed feedback LD (DFB-LD), a photodiode (PD), a wavelength division multiplexed (WDM) filter, and a polarization independent isolator placed between the WDM filter and the optical fiber. The stray light emitted from the LD and scattered by optically discontinuous interface is prevented from returning to the LD by the isolator. Although the isolator shifts the optical axis of the receiving optical signal emitted from the optical fiber, the PD with a wide optical sensitive surface may receive almost whole portion of the receiving optical signal.