428 results about "Polarization plane" patented technology

An apparatus and method to determine the surface orientation of objects in a field of view is provided by utilizing an array of polarizers and a means for microscanning an image of the objects over the polarizer array. In the preferred embodiment, a sequence of three image frames is captured using a focal plane array of photodetectors. Between frames the image is displaced by a distance equal to a polarizer array element. By combining the signals recorded in the three image frames, the intensity, percent of linear polarization, and angle of the polarization plane can be determined for radiation from each point on the object. The intensity can be used to determine the temperature at a corresponding point on the object. The percent of linear polarization and angle of the polarization plane can be used to determine the surface orientation at a corresponding point on the object. Surface orientation data from different points on the object can be combined to determine the object's shape and pose. Images of the Stokes parameters can be captured and viewed at video frequency. In an alternative embodiment, multi-spectral images can be captured for objects with point source resolution. Potential applications are in robotic vision, machine vision, computer vision, remote sensing, and infrared missile seekers. Other applications are detection and recognition of objects, automatic object recognition, and surveillance. This method of sensing is potentially useful in autonomous navigation and obstacle avoidance systems in automobiles and automated manufacturing and quality control systems.

In order to reduce mutual interferences between POLMUX and signals, the signals are transmitted with differed to each other carrying signals, thereby making it possible to obtain the circular polarization of each resulting POLMUX signal. Each second POLMUX signal is transmissible with an opposite circular polarization. In order to reduce also interferences when only one modulated data signal is transmitted through a POLMUX channel, a polarization plane of modulated data signals of each second POLMUX channel is turned at 45°. In a variant, polarization multiplex signals are produces and the resulting polarizations thereof in adjacent channels are perpendicular to each other.

A bidirectional optical module according to the present invention emits light to an optical fiber and allows returning light from the optical fiber to enter and includes a plurality of light emitting elements that emit light to enter the optical fiber, a light receiving element that receives light having exited the optical fiber, and a non-reciprocal unit for making an optical path in a forward direction from the light emitting element to the optical fiber and an optical path in a backward direction from the optical fiber to the light emitting element different. Then, polarization planes of light incident on the optical fiber after being emitted from the plurality of light emitting elements are mutually orthogonal, and the non-reciprocal unit emits returning light of light emitted from the plurality of light emitting elements from the optical fiber toward the light receiving element to one light receiving element.

The present invention provide an optical circuit device having: an optical circuit; a polarization beam splitter / combiner for splitting an incoming light beam into two polarization beams and combining the two polarization beams into an outgoing light beam; a first optical waveguide and a second optical waveguide for connecting the optical circuit and the polarization beam splitter / combiner and receiving the two polarization beams independently; and a polarization rotator, arranged on the first optical waveguide, for rotating a polarization plane of one of the two polarization beams split by the polarization beam splitter / combiner so as to match a polarization plane of the other of the two polarization beams, the optical circuit, the polarization beam splitter / combiner, the first optical waveguide, the second optical waveguide and the polarization rotator being integrated on a planar substrate.

The present invention provides an optical switch in which a switching operation is not affected even when the polarization state of a control light varies. The optical switch comprises a loop-form optical waveguide loop circuit formed from an optical nonlinear medium, control light input means of phase control means for inputting the control light into the optical waveguide loop circuit, a wavelength demultiplexing / multiplexing circuit, and a phase bias circuit. The optical waveguide loop circuit is constituted by an optical path formed from a first polarization-maintaining single-mode fiber extending from an optical demultiplexer / multiplexer to the control light input means, an optical path formed from a second polarization-maintaining single-mode fiber extending from the control light input means to the wavelength demultiplexing / multiplexing circuit, and an optical path formed from a fourth polarization-maintaining single-mode fiber extending from the wavelength demultiplexing / multiplexing circuit and returning to the optical demultiplexer / multiplexer. The wavelength demultiplexing / multiplexing circuit is formed as a loop-form optical waveguide loop circuit by a third polarization-maintaining single-mode fiber connecting a wavelength demultiplexer and a multiplexer, a fifth polarization-maintaining single-mode fiber connecting the wavelength demultiplexer and a polarization plane rotation portion, and a sixth polarization-maintaining single-mode fiber connecting the polarization plane rotation portion and the multiplexer. The phase bias circuit is inserted at a point on any one of the first through fourth polarization-maintaining single-mode fibers.

A polarization lidar system capable of remotely identifying characteristics of atmospheric aerosol particles by transmitting a polarized beam of light and analyzing polarization characteristics of received backscatter is disclosed. The transmitter features high pulse energy to remotely identify aerosol particles with substantially one pulse. The transmitter employs a thin film plate polarizer and a Raman wavelength shifter to achieve eye-safe, single-plane linearly polarized energy. The transmit beam and receiver field of view are coaxial. The receiver employs a telescope, a collimating lens, and a beam splitter. The beam splitter splits the received backscatter into a single-plane polarized beam whose polarization plane is parallel to the plane of transmission and a single-plane polarized beam whose polarization plane is perpendicular to the plane of transmission. Each split beam is directed through separate focusing lenses onto separate detectors. The detector signals are amplified and processed to remotely determine atmospheric aerosol particle characteristics.

A fire alarm having an electronic evaluator, an optical module, a temperature sensor, and at least one combustion gas sensor, where the electronic evaluator diagnoses one of a plurality of fire types and selects an application-specific algorithm based on the diagnosed fire type. The electronic evaluator uses the signals from the sensors to diagnose at least one of a plurality of types of fire. The fire alarm may have at least one polarization filter which may be an active polarizer with electrically adjustable polarization plane.

A head-up display optical film includes: a first optical layer configured to convert the polarization plane of incident light by 90 degrees; a second optical layer configured to convert the polarization plane of incident light by 90 degrees; and an intermediate optical layer sandwiched between the first optical layer and the second optical layer and having a refractive index that is different from the refractive index of the first optical layer and from the refractive index of the second optical layer.

An optically pumped magnetometer having a single optical axis using atomic electron spin or nuclear spin includes a detection unit configured to detect an angle of a polarization plane of probe light having components of linear polarization and a modulation unit configured to apply a modulation to the angle of the polarization plane of the probe light having the components of linear polarization. The modulation unit is configured to control an offset in applying the modulation to the angle of the polarization plane of the probe light having the components of linear polarization according to the angle of the polarization plane of the probe light detected by the detection unit.

There is provided an optically pumped magnetometer, in which a pump light having a first wavelength to spin-polarize a first alkali-metal atom group is made to enter a cell containing the first alkali-metal atom group and a second alkali-metal atom group interacting via spin exchange with the first alkali-metal atom group, a probe light having a second wavelength different from the first wavelength to measure spin polarization of the second alkali-metal atom group is made to enter the cell to form the same optical axis as the pump light, a wavelength discrimination unit is provided to discriminate between the pump light and the probe light that passed through the cell depending on a different in wavelength, and the rotation angle of a polarization plane of the probe light that passed through the cell is measured so that the degree of flexibility of the device layout can be increased.

A display device for a vehicle according to the present invention includes a display which emits an emission display light having a polarization plane in a specific direction, an illumination light source which illuminates the display, and a phase difference plate which is disposed facing the display in a state where a fast axis is shifted by a predetermined angle with respect to the polarization plane of the emission display light emitted by the display.

A direction of a power feed patch relative to a rod-shaped antenna is set so that a short axis thereof substantially orthogonally crosses a plane containing an intersection between the short axis and a long axis of the power feed patch of a patch antenna and an axis of the rod-shaped antenna. As a plane of polarization of a linearly polarized electromagnetic wave radiated from the rod-shaped antenna is thereby caused to substantially coincide with a direction of the long axis of the power feed patch and to substantially orthogonally cross a direction of the short axis, even if a powerful wave of a higher frequency than a desired frequency to be received by the patch antenna and difficult to be removed by a band pass filter of a low-noise amplifier circuit is radiated from the rod-shaped antenna, field components of the high frequency electromagnetic wave in the direction of the short axis will become virtually zero.

An optically pumped magnetometer and a magnetic sensing method acquire information as to strengths of magnetic fields in two different directions. A pump light having a circularly polarized component, first probe light having a liner polarized component and second probe light having a linearly polarized component are emitted to a cell containing a group of alkali metal atoms so as to form a crossing region A magnetic field applying unit applies a static magnetic field in a direction of the pump light incident on the crossing region during the emission of the pump light, the first probe light and the second probe light. And, information as to strengths of magnetic fields in two different directions perpendicular to the direction of the static magnetic field in the cell from the rotation angles of a polarization planes of the first and second probe lights during passage through the cell is calculated.

A light emitting device capable of improving light extraction efficiency is provided. The light emitting device includes: a laser generator which outputs linearly polarized laser light; a fluorescent body which is irradiated with the laser light from the laser generator; and a reflective polarization filter which is arranged in a region through which the laser light outputted from the laser generator passes. The reflective polarization filter is formed to transmit linearly polarized light of the laser light and reflect linearly polarized light having a polarization plane which is perpendicular to a polarization plane of the linearly polarized light of the laser light.

A method and apparatus for producing a hologram using a two-beam laser interference exposure process, comprising the steps of using as a light source a femtosecond laser having a pulse width of 900-10 femtoseconds and a peak output of 1 GW or more and capable of generating a pulse beam at or close to the Fourier transform limit, dividing the pulse beam from the laser into two by a beam splitter, controlling the two beams temporally through an optical delay circuit and spatially using plane and concave mirrors each having a slightly rotatable reflection surface to converge the beams on a surface of or within a substrate for recording a hologram at an energy density of 100 GW / cm.sup.2 or more with keeping each polarization plane of the two beams in parallel so as to match the converged spot of the two beams temporally and spatially, whereby a hologram is recorded irreversibly on the substrate formed of a transparent material, semiconductor material or metallic material.

The invention relates to ophthalmology and is used for treating keratoconus. The inventive method comprises forming one or more radiation areas of different shape, comprising concentric circles, arcs, parallel lines, cells, grids, spirals or other geometrical figures. In the other variant, the method comprises polarizing UV radiation and adjusting the depth of the UV radiation action by directing the UV radiation polarization plane at an angle of 1-180° to the plane of light polarization by the cornea, thereby using the effect of light polarization by the cornea. The device for treating keratoconus comprises, positioned on the optical axis common with an UV radiation source optical focusing elements and a diaphragm. The diaphragm is situated on the optical axis common with the UV radiation source and is made in the form of a mask with alternating transparent and shaded elements in the form of concentric circles, arcs, parallel lines, cells, grids, spirals or other geometrical figures. In the other variant, the device comprises, situated on the optical axis common with the UV radiation source, the optical focusing elements, the diaphragm and a polarisor.

An image processor (101) according to a preferred embodiment of the present invention includes a polarized light source (102) and a polarization camera (103). In shooting an object (104), the object is irradiated with polarized light (105) that rotates its polarization plane. The polarized light is reflected from the object's surface and the polarized reflected light (106) reaches the polarization camera (103), thereby recording an image there. The polarization camera (103) includes a polarization image sensor (201), an intensity and polarization information processing section (202), a polarization plane control section (204), and an image capturing control section (205). By capturing an image every time the polarization plane control section (204) changes the polarization state of the polarized light, an intensity image Y and a polarization phase image P are obtained in association with each polarization state. Using these images, a resolution increasing processing section (203) generates a high-resolution normal image (208) and a high resolution intensity image (209).

A heating element for an inside surface of a front-end module / bumper for a motor vehicle. The heating element is operatively connected to a radar transmitting / receiving unit. The heating element comprises a heating film formed of a polymer, an array of conductor strips integrated into the heating film, and an electronic control element that controls the conductor strips. The array of conductor strips is divided into an inner region through which a radar beam from the radar transmitting / receiving unit is transmitted, and an outer region through which the radar beam is not transmitted. The conductor strips in the inner region are inclined by angles of about 45° to about 90° relative to a polarization plane of the radar beam. The conductor strips in the outer region are arranged in a meandering pattern.

Provided is a quantum cryptography communication apparatus capable of preventing a go photon pulse from being phase modulated and also capable of freely selecting any repetitive frequency of a light source. In the quantum cryptography communication apparatus, a quantum receiver apparatus includes: a light source; an optical path loop having a multiplexing / interfering means for generating time difference twin photon pulses from the photon pulses of the light source and for multiplexing and causing interference between a signal optical pulse corresponding to a retrograde quantum and a reference optical pulse; a bypass optical path having a phase modulator for phase modulating only the received reference optical pulse; and a photon detector for observing the interfered light passed through the optical path loop, and a quantum transmitter apparatus includes: a polarized wave rotating means for rotating polarization planes of the twin photon pulses at a right angle in a non-reciprocal manner; a phase modulator for phase modulating and returning the signal optical pulse passed through the polarized wave rotating means, to the quantum receiver apparatus; and a beam attenuating means.

A fiber optic polarimetric strain sensor and associated data acquisition system capable of all-optical measurements of physical parameters, such as structural strain, gas and liquid pressure, acceleration and vibration, gas and liquid flow rate, and force without fire and explosion hazards associated with conventional strain gage technologies, such as resistance foil strain gages. The polarimetric strain sensor houses a sensitive element—a length of single mode optic fiber—changing polarization of a single-mode optical signal running in the fiber under some mechanical affects, specifically twisting and radial compressing. A linearly-polarized light passes the sensor, which causes polarization deviation of the light, particularly, polarization plane rotation under mentioned above twisting or compressive stresses applied to a sensitive element of the sensor. A multi-channel time division multiplexing data acquisition system that includes polarization analyzer indicates the polarization state deviation caused by the strain, so allow measuring the parameters. The invention may be embodied for measurements of any phenomenon that can be transformed in stress on an optical fiber.

The invention discloses a high-sensitivity all-optical cesium atom magnetometer and belongs to an atom magnetometer. The magnetometer is provided with a magnetic shielding tube, a Cs atom gas chamber is placed in the magnetic shielding tube, a three-axis Helmholtz coil is placed around the Cs atom air chamber, and a pump light opening, a detection light opening and am emergent light opening are respectively formed in the magnetic shielding tube. The Cs atom gas chamber is cuboid, four surfaces, used for passing through deflection light to form reflection, excepting incident light and emergent light local parts of the detection light, the Cs atom air chamber are plated with polarization-maintaining films, and the other two surfaces used for passing through pump light are not plated with films. The detection light emitted by a detection light laser enters the Cs atom gas chamber through a polarizing film and a small aperture diaphragm and is emergent after reflected on all the surfaces of the gas chamber repeatedly, the polarization plane of the emergent light rotates by a one-degree angle, one drip of Cs, 100Torr of He gas and 20Torr of N2 gas are put into the Cs atom gas chamber, and the Cs atom gas chamber works at normal temperature. The high-sensitivity all-optical cesium atom magnetometer has the advantages of being simple in structure and still capable of keeping high sensitivity without being heated.

A polarization viewer comprising a mechanism for forming a broadview image having a spectral width greater than 2 angstroms and 0.50° based on polarization information of a scene. The polarization viewer is also comprised of a mechanism for providing polarization information to the forming mechanism. The providing mechanism is in communication with the forming mechanism. In a first embodiment, the providing mechanism includes a camera mechanism in communication with the forming mechanism. The camera mechanism includes a fixed polarizer analyzer disposed such that electromagnetic radiation entering the camera mechanism passes through the polarizer analyzer. The providing mechanism can also include a mechanism for steering a polarization plane of the radiation. The steering mechanism is disposed such that radiation passing through the polarizer analyzer first passes through the steering mechanism. The steering mechanism preferably includes a first twist crystal and at least a second twist crystal aligned with the first twist crystal such that radiation passing through the first crystal then passes through the second crystal. Each crystal has a first state and a second state. The first state does not effect the polarization plane of the radiation as the radiation passes through the crystal. The second state rotates the polarization plane of the radiation as the radiation passes through the crystal.

To provide optical modules and optical transmission devices that are suitable for communication forms using multimode optical fibers, an optical module includes a surface-emitting type semiconductor laser that emits polarized light oscillating in a multimode which is preferentially oriented in two given polarization axes, and an optical member that demonstrates at least one function among a transmission function, a reflection function, a refraction function, and a diffraction function alternatively to a predetermined polarization. The optical member is disposed such that a principal plane thereof intersects with a traveling direction of emission light of the surface-emitting type semiconductor laser and a polarization axis of the polarization plane does not overlap with the polarization axes of the emission light of the surface-emitting type semiconductor laser.

A combined radiation pulse of a predetermined energy is provided by temporally and spatially overlapping four pulses from four extra-cavity, frequency-tripled lasers. Frequency tripling is effected in each laser by a second-harmonic generating crystal followed by a third-harmonic generating crystal. One of the lasers includes a Pockels cell preceding the second-harmonic generating crystal. The third harmonic pulse from this laser is the fourth and last delivered in the sequence. The total available energy in three of the pulses is less than the predetermined energy. The cumulative integrated energy of the pulses is determined while the pulses are being delivered. When the energy is determined to have reached the predetermined value, the Pockels cell is activated to rotate the polarization plane of fundamental radiation entering the second-harmonic generating crystal, thereby terminating generation of the fourth pulse and delivering the combined radiation pulse at the predetermined energy.

To provide optical modules and optical transmission devices that are suitable for communication forms using multimode optical fibers, an optical module includes a surface-emitting type semiconductor laser that emits polarized light oscillating in a multimode which is preferentially oriented in two given polarization axes, and an optical member that demonstrates at least one function among a transmission function, a reflection function, a refraction function, and a diffraction function alternatively to a predetermined polarization. The optical member is disposed such that a principal plane thereof intersects with a traveling direction of emission light of the surface-emitting type semiconductor laser and a polarization axis of the polarization plane does not overlap with the polarization axes of the emission light of the surface-emitting type semiconductor laser.

A liquid crystal display including includes a surface light source device of side light type for backlighting a liquid crystal panel. A primary light source supplies light to a guide plate. Emission from an emitting face impinges on a polarization separating element through a prism sheet. A polarization component which is directionally corresponding to a transmission polarization plane M12 is supplied to the liquid crystal panel. Reflection at the polarization separating element provides returning light which is subject to inside reflection by projection rows formed on a back face of the guide plate, thereby causing the guide plate to emit afresh recycling light. This recycling light, which is rich with the polarization component directionally in accordance with transmission polarization plane M12, impinges again on the polarization separating element. The projection rows formed on the back face run in a direction (first direction) which is generally vertical with respect to an incidence face of the guide plate while obliquely crossing with respect to both reflection polarization plane M2 and transmission polarization plane M12 of the polarization separating element. Projection rows formed on an inner face of the prism sheet run in another direction (second direction) which is generally parallel with respect to the incidence face of the guide plate. The polarization separating element and the prism sheet may be unified.

The invention discloses an octagonal-ring plane bipolarized broadband phased-array antenna based on strong mutual coupling effects. The antenna comprises a radiation unit layer which is printed on a super-thin medium layer and a guide unit layer; and the radiation unit layer and the guide unit layer are composed of octagonal ring units which are periodically arrayed. The tail ends of the octagonal ring units in the radiation unit layer respectively extend to the tail ends of the adjacent octagonal ring units to form an interdigital capacitor which is capable of enhancing a capacitance coupling amount between the units. The octagonal-ring antenna unit provided by the invention is particularly suitable for the design of a super-broadband bipolarized plane phased-array antenna.

A method of coupling laser-radiation into an optical fiber includes providing a stack of diode-laser bars and first and second parallel mirrors, the second mirror is selectively reflective only for one polarization plane of the laser-radiation. Each of the diode-laser bars includes at least two spaced-apart diode-laser emitters each emitting a plane-polarized beam of laser-radiation having a fast axis and a slow axis. The laser-radiation beams are collimated in the fast axis by a cylindrical lens located in front of each bar. In one arrangement the polarization orientation of one collimated beam from each diode-laser is rotated by 90 degrees and transmitted through the selectively-reflective mirror. The other collimated beam from each diode-laser bar is reflected onto the selectively-reflective mirror by the first mirror and reflected from the selectively-reflective mirror such that the reflected beam combines with the transmitted beam to form a combined beam. As many combined beams are formed as there are diode-laser bars in the stack. These combined beams are focused into an entrance face of the optical fiber.

A wavelength converter which employs an optical fiber and has high converter efficiency. The polarization planes of a signal light and an exciting light outputted from a laser diode (LD) (103) are respectively controlled by polarization controllers (PC's) (101 and 104) and the phases of the lights are respectively modulated by phase modulators (PM's) (102 and 105) in accordance with modulation signals outputted form an oscillator (110). Then, the output lights form the PM's (102 and 105) are multiplexed by a coupler (106). After the multiplexed signal light and exciting light are amplified by an optical amplifier (EDFA) (107), they are imputed to a dispersion shift fiber (DSP) (108). After wavelength transformation (four light waves mixing (FWM) is practiced in the DSP, and FWM light is outputted through a band-pass filter (BPF) (109).

There is provided an optically pumped magnetometer, in which a pump light having a first wavelength to spin-polarize a first alkali-metal atom group is made to enter a cell containing the first alkali-metal atom group and a second alkali-metal atom group interacting via spin exchange with the first alkali-metal atom group, a probe light having a second wavelength different from the first wavelength to measure spin polarization of the second alkali-metal atom group is made to enter the cell to form the same optical axis as the pump light, a wavelength discrimination unit is provided to discriminate between the pump light and the probe light that passed through the cell depending on a different in wavelength, and the rotation angle of a polarization plane of the probe light that passed through the cell is measured so that the degree of flexibility of the device layout can be increased.