207 results about "Beam polarization" patented technology

There is provided a device capable of switching between a state that displays a high-quality image and a mirror status in which is obtained an easy-to-view reflection image suitable for a person to view his/her own face or figure. An image display portion 1000 that emits image light 3001, reflective polarization selection means 300 that transmits a first linear polarization component emitted from the image display portion 1000 and reflects a second linear polarization component, whose polarization axis is orthogonal to that of the first linear polarization component, a transmission polarization axis variable portion 400 capable of selecting between one of a state that changes the polarization axis of incident linearly polarized light and a state that does not change the polarization axis of incident linearly polarized light, and a polarization selection member 500 which, of the incident light, absorbs the first linear polarization component and transmits the second linear polarization component, whose polarization axis is orthogonal to that of the first linear polarization component, are disposed in this order. In this case, absorbing polarization selection means 208 is disposed at the image display portion 1000, and the first linear polarization is emitted as the image light.

The present invention relates to confocal self-interference microscopy. The confocal self-interference microscopy further includes a first polarizer for polarizing reflected or fluorescent light from a specimen, a first birefringence wave plate for separating the light from the first polarizer into two beams along a polarizing direction, a second polarizer for polarizing the two beams from the first birefringence wave plate, a second birefringence wave plate for separating the two beams from the second polarizer into four beams along the polarizing direction, and a third polarizer for polarizing the four beams from the second birefringence wave plate, in the existing confocal microscopy. Optic-axes of the first and second birefringence wave plates exist on the same plane, optic-axes of the first and second birefringence wave plates are inclined from an optical axis of the entire optical system at a predetermined angle, and self-interference spatial periods of the first and second birefringence wave plates are different from each other.

Provided are techniques for generating optical vector beams (e.g., radially and azimuthally polarized light) using passive or active phase stable optical interferometry. Techniques may split an input optical beam into at least two output beams, and then couple those beams simultaneously into a passively phase stable optical interferometer. Beam splitting may be achieved by a diffractive optical element and coupling may be achieved by a single refractive optical device (lenses) or by a single mirror device (e.g., parabolic and spherical). The interferometer may provide the ability to manipulate (or transform) the polarization of part of the wavefront of each beam, as well as the ability to manipulate (or transform) the phase of part of the wavefront of each beam, such that the beams when combined have a vector beam polarization state.

The invention discloses a multi-channel vector holographic polarization multiplexing method based on a birefringent medium metasurface, and belongs to the technical field of micro-nano optics and holographic multiplexing application. The method comprises the following steps that: the metasurface for achieving the holographic polarization multiplexing is composed of nano column arrays with rectangular cross sections and different geometric dimensions and different azimuth angles; by changing the geometric size and azimuth angles of the nano column unit, the phase and polarization state of the emergent light beam are randomly regulated and controlled by the metasurface; holograms corresponding to different mutually independent original images are obtained by using a GS algorithm; according to the obtained holograms, the geometric size and azimuth angles of the nano column unit are determined by coding so as to generate a processing file of a corresponding medium metasurface structure; the metasurface of the transmission-type medium is processed by adopting a micro-nano processing process of electron beam etching; through the selection of the polarization states of the incident lightbeam and emergent light beam, the combination and multiplexing of seven different polarization images of twelve different polarization channels are achieved.

An optical beam synthesizer formed on a single chip is provided. It allows M-PSK modulation for both beam polarizations. The synthesizer comprises an optical pulse shaper and two M-PSK modulators for each polarization. A single-chip-integrated analyzer is provided to receive a modulated data. Analyzer comprises a pulse shaper operating as an optical sampler and a pair of 90-degrees optical hybrids for each polarization. Each optical hybrids mix incoming portions of the modulated beams with portions of the local oscillator beams. Both the synthesizer and the analyzer include a set of mirrors located on the back and front surfaces of the chips to create compact designs. The output beams from the analyzer are detected by a set of balanced photodiodes, and the data is recovered. It is another object of the invention to provide a communication system for data transmission having the synthesizer and the analyzer.

The invention discloses a method and device for high-accuracy and small-angle measurement, wherein the method comprises the following steps: polarizing and splitting the reference light beam which is obtained after the collimation processing to obtain the first linearly polarized light; converting into the circularly polarized light and radiating to a measuring target mirror after the beam expansion; detecting the reverse return of the light beam which is reflected by the target mirror; carrying out the beam contraction and the secondary conversion to obtain the second linearly polarized light; polarizing and splitting the second linearly polarized light again and dividing the second linearly polarized light into the reflected light and the transmission light which have the light intensity ratio of 1 to 1; respectively radiating the two beams of light to two prisms to be reflected; and respectively receiving and processing the reflected light signals through two detectors. The device disclosed by the invention comprises a laser emitting unit, a beam expansion lens unit, a measuring target mirror unit and a differential detection unit, wherein the laser emitting unit comprises a light source, a single mode fiber, a collimation lens, a polarization splitter and a lambda/4 wave plate; and the differential detection unit comprises the splitter, the two prisms and the two detectors. The method and device disclosed by the invention have the advantages of ultrahigh accuracy and large measuring range.

The present invention provides improved optical switches in which no mechanical movement is required to direct optical pathways between plural fiber ports and light transmission is bi-directional. Advantageously, the inventive switches permit bi-directional light transmission. The inventive switches also incorporate light bending devices to allow two fibers to be coupled to the light beams using a single lens for compactness. In the inventive switch, an optical signal is spatially split into two polarized beams by a birefringent element, which passes through a polarization rotation device that comprises waveplates, walk-off elements, and an electrically controllable polarization rotator, and recombine into an output fiber, achieving polarization independent operation. The switches of the present invention rely on electro-magnetically or electro-optically switching the beam polarizations from one state to another to rapidly direct the light path.

The invention manages to provide a stable and fast differential quantum key distribution method and system thereof. At transmitting end, with a continuous laser source, the quantum codes are prepared using two approaches: 1) using the beam-splitting, polarization-independent and phase-stabilizing approach to prepare the stable quantum code; 2) using polarization approach to directly prepare stable quantum code. At receiving end,differential phase-Faraday-Micheal test approach is used to directly receive the quantum information.

The invention discloses a fast polarization detector and a detecting method adopting the detector. The fast polarization detector comprises a polarization detecting module, a light intensity detector and a signal processing device connected with the output end of the light intensity detector, the polarization detecting module, the light intensity detector and the signal processing device are sequentially arranged on a light path, the polarization detecting module comprises at least three polarization detecting channels, and the polarization detecting channels carry out simultaneous split beam polarization detection on the same polarization light beam to be detected, so that emergent light split beams passing through the polarization detecting channels comprise different polarization information. The light intensity detector can detect the light beams with the number not smaller than that of the polarization detecting channels, the light intensity detector records the light intensity information of the emergent light beams and outputs the light intensity information of the emergent light beams to the signal processing device, and the signal processing device determines the polarization state of the polarization light beam to be detected according to the light intensity information of the emergent light beams and the polarization character of the polarization detecting channels. The fast polarization detector can measure the polarization state of light simultaneously, fast and accurately, and is simple in structure and low in cost.

The invention relates to an adjustable ring-shaped vector beam generating system. The prior art has high incident beam requirements, and cannot realize the ring-shaped vector beam and the beam size adjustment. In the invention, the incident beam sequentially passes through a beam expanding shaper, an external reflection circular conical surface reflector, a cylindrical curved polarizer, an internal reflection circular conical surface reflector, and two halfwave plates positioned in parallel; after a light source emergent beam passes through the beam expanding shaper and the external reflection circular conical surface reflector, a radial propagating beam is formed; a ring-shaped rotation vector polarized beam is formed by the reflection of the internal reflection circular conical surface reflector after the radial propagating beam passes through the cylindrical curved polarizer; the polarization state is changed by adjusting the optical axis angle of the two halfwave plates through a rotary motion part; and the transverse size of the beam is changed by adjusting the space between the external reflection circular conical surface reflector and the internal reflection circular conical surface reflector through an axial motion part. The invention has the advantages of low incident beam requirements, ring-shaped vector beam output, convenient beam polarization state and transverse size adjustment, etc.

A grating heterodyne interference auto-collimation measuring device mainly comprises a two-frequency laser, a 1/4 wave plate, a beam splitting system, a photoelectric conversion system, a polarization beam splitter, a reflector and a grating. The two-frequency laser emits two-frequency laser which passes the 1/4 wave plate and which then turns into two mutually-perpendicular linearly-polarized beams. The beams entering the beam splitting system are divided into three beams; one beam enters a reference light path photoelectric conversion system; last two enter a positive-negative gage beam polarization beam splitter. In the laser entering the polarization beam splitter, a reflected beam S is reflected to the grating by the reflector, and an incident angle is set into an auto-collimation angle of the corresponding diffraction order; through reference light information, horizontal and vertical displacements of the grating can be known. The auto-collimation right angle is set not depending on grating displacements. Therefore, the grating heterodyne interference auto-collimation measuring device is applicable to measuring horizontal large-travel displacement and vertical displacement.

A method for controlling the shape of the area machined by a pulse of laser light on a surface, such that the shape has a desired elliptical shape with its major axis aligned in a desired direction and the length of this major axis is less than or equal to a diameter of a beam spot. The pulse is generated and focused to the beam spot within a target area. The polarization of the pulse is adjusted to be elliptically polarized with an axis of the polarization ellipse oriented in the desired direction. The ellipticity of the polarization of the pulse is adjusted such that the pulse of laser light has contours of constant machining capacity on the workpiece surface, which have a similar shape to the desired shape. The fluence of the pulse light is controlled such that the area machined by the pulse is substantially the desired shape.

Device and method for measuring complex reflectance using a light source for generating a light beam with known polarization state, a lens for focusing the beam onto a sample surface such that various rays within the focused beam create a spread of angles of incidence θ, a waveplate for retarding one polarization state of the beam, a polarizer for generating interference between beam polarization states, and a detector with a two dimensional array of detector elements for generating intensity signals in response to the beam, wherein each detector element corresponds to a unique angle of incidence θ and azimuthal angle φ of the reflected beam. A processor calculates magnitude and phase values for the reflected beam by using the intensity signals corresponding to at least one incident angle θ and a plurality of azimuthal angles φ within the at least one incident angle θ sufficient to enable a meaningful Fourier analysis thereof.

A four-wave mixing squeezed light source includes: a mixing medium having chi(3) non-linear characteristics including two atomic ground states coupled to each other by transitions through optically-excited states; a pump beam having a polarization and a frequency, said frequency being near the ground-to-excited atomic transition but far enough from the atomic transition such that the pump beam is substantially unabsorbed; and a probe beam having a polarization that is orthogonal with respect to the pump beam polarization, the probe beam having a frequency of the pump beam frequency plus or minus a frequency splitting of the two atomic ground states. The mixing medium, the pump beam and the probe beam interact to produce a phase conjugate beam having a polarization that is orthogonal to the pump beam polarization, such that the beams are non-degenerate with the pump beam, and the probe beam is amplified.

Methods for spatially resolved spin resonance detection in a sample of material, with a resolution as small as 0.5 μ m –1 mm. In one embodiment, a coupler having at least one pair of degenerate orthogonal modes provides an evanescent input signal along one coupler axis to the sample, to which a magnetic field is applied, and senses a spin interaction signal along another coupler axis. In another embodiment, an evanescent input signal is applied to the sample along one of two identical transmission line resonators, and a difference of the two resonator signals provides a spin interaction signal. In another embodiment, a polarized laser beam provides an evanescent input signal to the sample, and the spin interaction signal is sensed according to a second beam polarization direction. Certain ferromagnetic or ferrimagnetic molecules, such as YIG, can be used to tag selected chemical and biological molecules, using spatially resolved spin resonance detection for interrogation.

Disclosed are spectroscopic ellipsometer and combined spectroscopic reflectometer/ellipsometer systems. The spectroscopic ellipsometer system portion includes polarizer and analyzer elements which remain fixed in position during data acquisition, and a step-wise rotatable compensator electromagnetic beam transmitting means, which serves to enable imposing a plurality of sequentially discrete, rather than continuously varying, polarization states on said beam of electromagnetic radiation. Further disclosed is a calibration procedure for said spectroscopic ellipsometer system portion of the invention which involves the gathering of, for each of a plurality of ellipsometrically distinct sample systems, spectroscopic data at a sequential plurality of discrete electromagnetic radiation beam polarization states, combined with providing of a mathematical model of the spectroscopic ellipsometer system and application of a mathematical regression procedure.

The invention discloses a method and device for measurement of nanometer resolution total reflection differential micrometric displacement. The device comprises a laser device, a single-mode fiber, a collimating lens, a polarizing beam splitter, a lambda/4 wave plate, a micro objective, a detected target lens, a rhombic prism, a convex lens, a differential detector and a driving and display unit. The method comprises steps as follows: after being filtered, collimated and split by polarization, laser sequentially passes through a fast axis and the lambda/4 wave plate and micro objective to reach the detected target lens, wherein the included angle between the lambda/4 wave plate and micro objective and the polarization direction of vertical incidence light beam is 45 degrees; after being reversed, the laser passes through the micro objective and lambda/4 wave plate, and then vertically enters the polarizing beam splitter again; then, the laser enters the rhombic prism, is subjected to total reflection in the rhombic prism, and exits; and finally, after being collected, the laser enters the differential detector for processing, thus obtaining a signal for reflecting the position change of the detected target lens, and displaying the position change of the detected target lens. The invention can be used for detecting the manometer resolution and can be widely applied to the industrial precision measurement and monitoring fields.

A tunable filter includes a polarizer, a polarization rotator, a diffraction grating and a diffraction grating adjustor. The polarizer polarizes a light beam and splits the light beam into first and second light beams. The polarization rotator rotates a plane of polarization of the first light beam at 90.degree. to generate a rotated light beam. The diffraction grating receives the rotated light beam and the second light beam. The diffraction grating adjustor adjusts the diffraction grating to change incident angles of the rotated light beam and second light beam.

The invention relates to a light beam polarization state adjusting rectifying system, composed of an incident beam expanding rectifying device, an external reflection cone reflector, a cylinder curved polarizer, an internal cone reflector, an incident 1/2 wave plate, an exit 1/2 wave plate and an exit beam expander, which arranged on a symmetrical optical axis in turn of an incident light beam optical path, wherein the incident light beam passes the incident beam expanding rectifying device to be reflected by the external reflection cone reflector to form a radial light beam, to be changed of light beam polarized state via the cylinder curved polarizer, to be reflected by the internal reflection cone reflector to form a circular vector light beam, the polarization direction can be adjusted by changing the optical axis angle of the two 1/2 wave plates and a circular vector polarization light beam of required size can be obtained after the exist beam expander. The light beam polarization state adjusting rectifying system can convert a non-rotation vector polarized light beam to a rotation vector polarized light beam, having low incident light beam requirements, high system stability and reliability, and easy adjustment of the light beam polarized state and the transverse size.