Abstract: A waveguide having a periodic structure and the excitation of exciton polariton as one form of interactions between radiation fields and matter systems are applied to light switching to provide an optical switch that is excellent in light intensity extinction ratio and operable at a speed in the terahertz order. The optical switch includes a polariton and photon interacting region (5) made of a grating (3) formed on a top face of a transparent substrate (2) and a semiconductor layer (4) with which the grating (3) is covered. The polariton and photon interacting region (5) is irradiated from a free space with a controllable light (7) having a preestablished wavelength and also from a free space with a control light (6) having a preselected wavelength to control the transmissivity of the controllable light (7) through the polariton and photon interacting region (5).

Abstract: A modular optical platform for selective wavelength switching that can be adapted to perform various other functions, such as dynamic gain equalization (DGE) and add/drop multiplexing (ADM) provides the versatility and modularity that will be essential to the future of the fiber optics industry. The basic platform includes a first lens for directing an optical signal, a diffraction grating for dispersing an optical signal into its component wavelength channels, a second lens for directing the component wavelength channels, and a modifying device for conducting one or more of a variety of functions including switching, DGE and ADM. The first and second lens are preferably replaced by a single concave reflective mirror having optical power.

Abstract: To provide an optical apparatus which controls an interface state to change a focal length by using an optical element having a container sealing first liquid that is conductive or polarized and second liquid that does not mutually mix with the first liquid with their interface in a predetermined form and electrodes provided in the container and of which optical characteristics change according to change of interface form due to application of voltage to the electrodes, and in particular an optical apparatus that controls a duty ratio of alternating current voltage applied to said electrodes for changing said interface form.

Abstract: A GTIFR interferometer, for use in an interleaver or in a deinterleaver, wherein the GTIFR interferometer includes a Gires-Toutnois interferometer with a 45 degree Faraday rotator between the mirrors of the Gires-Tournois interferometer and further includes a 22.5 degree Faraday rotator in the light path to the Gires-Tournois interferometer and an interleaver or deinterleaver that contains one GTIFR. A dispersion compensated GTIFR interleaver includes a second Gires-Tournois interferometer for providing chromatic dispersion compensation.

Abstract: Removal of unnecessary reflected light in an image display apparatus employing reflective spatial light modulators to enable display of a high-quality image, having good contrast and no occurrence of the ghosting phenomena. Modulated light of each color synthesized by a fourth modulated light beam splitter 16 is injected into a projection lens 19 as circularly polarized light by a &lgr;/4 plate 18, reflected light (R′, G′, B′) reflected from the projection lens 19 does not return to the respective spatial light modulating elements 7, 11 and 12 for each color.

Abstract: An optical modulator and an image projection display apparatus using it can reduce a size of a system and improve efficiency, by attaching a reflection plane on a nonlinear matter. The optical modulator in accordance with the present invention includes a nonlinear matter which is divided into predetermined regions having a direction of a polarization which is periodically reversed, an electrode which is joined with the upper and lower sides of the nonlinear matter, for applying an electric field to the polarization region at the lower portion of the nonlinear matter and a reflection plane which is joined to the rear surface of the nonlinear matter, for reflect an incident light to an incident region again.

Abstract: A variable optical attenuator including: a birefringent element positioned to separate an input optical signal into two spatially separated, orthogonally polarized beams; a LC modulator positioned to receive the orthogonally polarized beams and selectively alter their polarizations; a reflective element positioned to reflect the beams back through the LC modulator and the birefringent element, wherein the birefringent element recombines orthogonally polarized components of the reflected beams to produce an output optical signal; and a controller coupled to the LC modulator to selectively cause the LC modulator to alter the polarizations of the orthogonally polarized beams, wherein during operation the controller is responsive to a request to variably attenuate the intensity of the output optical signal relative to the intensity of the input optical signal to one of multiple non-zero attenuation settings.

Abstract: Apparatus for wavelength conversion includes a first optical be splitter, a first leg and a second leg each splitting from the first optical beam splitter, a first optically passive nonlinear device disposed in the first leg, a second optically passive nonlinear device disposed in the second leg and a second optical beam splitter joining the two legs beyond the optically passive nonlinear devices. An unmodulated optical signal splits between the two legs. When no other beam is in the second leg, all optical signals exit the second beam splitter at a first port. When another (modulated) beam is imparted to the optically passive nonlinear device in the second leg, an imbalance is created at the second beam splitter such that some portion of the unmodulated optical signal exits at a second port of the second beam splitter in a modulated manner.

Abstract: An optical polarization modulator (OPM) for use in an optical communication system includes two polarizing beam splitters (PBSs) and an adjusting stage coupled between the PBSs. One PBS receives an input optical signal with an arbitrary state of polarization (SOP) and splits it into its TE and TM components. The adjusting stage can change the amplitude and/or relative phase between the TE and TM components to help achieve a desired state of polarization (SOP). The ACS and PCS may include MZIs to both adjust the amplitude and the relative phase difference between the TE and TM components. Alternatively, the OPM may include an amplifier and a phase shifter for each component. The second PBS combines the adjusted components to form the output signal with a desired SOP. Another embodiment of the OPM includes an Y-junction coupler, two plasma optical-effect silicon phase shifter stages, a 2×2 3-dB coupler and a PBS.

Abstract: Provided are a polarization mode dispersion (PMD) compensator and method for automatically and rapidly compensating PMD occurring in an optical transmission fiber in a high-speed optical transmission system. The polarization mode dispersion compensator includes a separator and a differential time delay remover. The separator aligns orthogonal first and second polarization components of a received optical signal with respect to two orthogonal axes of a polarization beam splitter using optical signal information output via a second path of a first path and the second path of the two outputs of the polarization beam splitter, splits the first and second polarization components, and transmits the first polarization component via the first path and the second polarization component via the second path. The differential time delay remover receives the first and second polarization components that have been split to remove a differential time delay between the first and second polarization components.

Abstract: Disclosed is an illuminating optical unit in an image display unit for displaying an image by irradiating a GLV (spatial modulation device) with a laser beam and modulating the laser beam based on an image signal inputted to the GLV, including a polarized light rotation means for equally dividing a polarized light component of the laser beam into a P polarized light component and an S polarized light component, a polarized light beam splitter for separating from each other the P polarized light component and the S polarized light component equally divided by the polarized light rotation means, and an optical path difference generation means for generating an optical path difference not less than the coherence length of the laser beam between the laser beam of the P polarized light component and the laser beam of the S polarized light component.

Abstract: A method for improving the bit error rate of a modulated optical signal transmitted over single mode fiber is provided. The modulating voltage supplied to a single arm or alternatively to both arms of a Mach-Zehnder modulator is increased to result in a reduced extinction ratio of the modulated optical signal. This results in an optimum optical signal with a reduced bit error rate at a receiver coupled to the Mach-Zehnder modulator.

Abstract: An active optical system and method for phase-shifting desired portions of an incoming optical wavefront. A control optics assembly receives an incoming optical wavefront and adjusts that incoming optical wavefront in accordance with first desired wavelength and beam propagation parameters. Spatial light modulator (SLM) addressing optics receives the control optics output wavefront and produces a desired beam size therefrom. An SLM receives the output from the SLM addressing optics and provides localized phased shifting of the resulting wavefront. The SLM comprises a microscopic array of pixelated silicon nanocluster elements and a voltage source for applying independently controlled voltages on desired nanocluster elements. SLM egressing optics receives the output of the SLM and returns the beam size of the wavefront to the initial beam size. The output of the SLM egressing element has desired portions of its phase shifted relative to the incoming optical wavefront.

Abstract: The present invention provides an improved switchable interleaved channel separator device. The switchable interleaved channel separator device utilizes an adjustable reflective non-linear interferometer, which performs both switching and wavelength polarization sorting functions, so that overall complexity of the device is reduced. Further, because the adjustable non-linear interferometer is a reflection element, signal light paths are folded back upon one another so as to realize an overall reduction in the device's size, as well as the capability of performing optical couplings predominantly or wholly at a single side or at adjacent sides of the device.

Abstract: An electro-modulating device for modulating light from a light source, as part of an opto-electronic communication network has a modulating medium for modulating light passing therethrough by varying an electric field applied across the modulating medium, an optical input-output surface, a light reflector, and electrodes for applying the varying electric field across the modulating medium. The input-output surface, the medium and the reflector are arranged so that light enters the medium through the input-output surface, travels through the medium towards the reflector, is reflected by the reflector to travel back through the medium towards the input-output surface, and exits the medium through the input-output surface. The electric field is transverse to light traversing the medium between the input-out surface and the reflector, to make it easier to couple an optic fiber to the input-output surface of the modulating medium.

Abstract: An optical frequency converter using reciprocating modulation includes a device that, taking n as a predetermined integer of 1 or more, modulates light of a predetermined frequency to produce an nth order sideband group thereof, a device that modulates the nth order sideband group to produce an (n+1)th order sideband group, and a device that selects a specific sideband from a plurality of sideband groups.

Abstract: An optical modulator drive circuit provides a different approach to driving an optical modulator than presently employed, resulting in a reduction in power dissipation of the drive circuit by as much as 80%. Therefore, this invention dissipates as little as 20% of power of the present drive circuits known in the art. The optical modulator may be a semiconductor electro-absorption modulator but the principle of the invention can be applied any other type of electro-optic modulator that relies on a voltage to modulate an optical signal.

Abstract: An optical switch for switching an incoming light signal to one of a number of output ports in a polarization independent manner. The optical switch includes a walk-off device, and a compensator which compensates for walk-off distance variations of two polarized beams, with orthogonal polarization directions, associated with the walk-off device.

Abstract: An electronic shutter apparatus and light shuttering method for a still image capturing device are provided according to the invention. In one embodiment, the apparatus includes a beam splitter positioned in an incoming light beam path and splitting the incoming light beam into a first light beam and a second light beam. The apparatus further includes first and second polarizing shutters respectively positioned in paths of the first and second light beams and capable of being electrically activated to transmit light and to respectively form first and second polarized light beams. A polarization orientation of light from the second polarizing shutter is in non-alignment with a polarization orientation of light from the first polarizing shutter. The apparatus further includes a beam combiner receiving and combining the first and second polarized light beams to form a substantially non-polarized resultant light beam. The resultant light beam is focused onto an image sensor.

Abstract: Techniques and systems for mitigating polarization-related signal degradation or distortions in birefringent optical links based on intra-bit polarization diversity modulation.

Abstract: A multi-gas sensor is provided which modulates a polarized light beam over a broadband of wavelengths between two alternating orthogonal polarization components. The two orthogonal polarization components of the polarization modulated beam are directed along two distinct optical paths. At least one optical path contains one or more spectral discrimination means, with each spectral discrimination means having spectral absorption features of one or more gases of interest being measured. The two optical paths then intersect, and one orthogonal component of the intersected components is transmitted and the other orthogonal component is reflected. The combined polarization modulated beam is partitioned into one or more smaller spectral regions of interest where one or more gases of interest has an absorption band.

Abstract: At least one qubit in a quantum computing device is created. At least one photon is placed into a superposition of quantum states. The quantum states each have an associated probability amplitude. The quantum states each are associated with a mode from a group of orthogonal modes. The probability amplitudes associated with the quantum states of the at least one photon are temporally separated thereby forming at least one qubit, the alternative values of which are thus temporally identifiable.

Abstract: Disclosed is a projector apparatus including a color separation optical system which separates illumination light into a plurality of color light components, a plurality of image forming panels illuminated with the plurality of color light components, respectively, a color synthesis optical system which synthesizes the light components from the plurality of image forming panels illuminated, a projecting optical system which projects light from the color synthesis optical system, and transparent substrates each arranged on at least one of incident and exit surface sides of the plurality of image forming panels, each of the transparent substrates holding a polarizer, wherein a surface area of at least one of the plurality of transparent substrates is larger than those of the remaining transparent substrates.

Abstract: A Mach-Zehnder interferometer is employed to implement phase modulation of an optical signal. The interferometer is biased at its maximum extinction point. The modulated optical signal may have a peak magnitude between approximately 30% and 80% of a maximum output power of the interferometer.

Abstract: An apparatus for processing an optical beam has at least one variable optical element to dynamically alter the polarization state of a polarized optical beam to form a polarization-altered optical beam. The polarization-altered optical beam includes elliptical polarization. The at least one variable optical element is a compound birefringent crystal with a designed retardation response to temperature variations. In one embodiment, the compound birefringent crystal has a designed retardation response that is substantially invariant with operating temperature variations. At least one wave plate processes the polarized optical beam. Each wave plate has a selected retardation, order of retardation, and orientation.

Abstract: The present invention provides an improved switchable interleaved channel separator device. The switchable interleaved channel separator device utilizes an adjustable reflective non-linear interferometer, which performs both switching and wavelength polarization sorting functions, so that overall complexity of the device is reduced. Further, because the adjustable non-linear interferometer is a reflection element, signal light paths are folded back upon one another so as to realize an overall reduction in the device's size, as well as the capability of performing optical couplings predominantly or wholly at a single side or at adjacent sides of the device.

Abstract: A, reciprocating optical modulation system includes a device that modulates light of a predetermined frequency by an integer multiple n to produce a group of nth order sidebands thereof; a device that modulates the nth order sidebands to produce (n+1)th order sidebands; and a device that selects at least part of the (n+1)th order sidebands.

Abstract: PL polarizers are disclosed which are characterized in a low degree of polarization in their absorption and a high degree of polarization in their emission. The invention also discloses methods to produce such PL polarizers. Also, the invention discloses display devices of high brightness and contrast which comprise at least one photoluminescent polarizer which is characterized in a low degree of polarization in their absorption and a high degree of polarization in their emission.

Abstract: Optical systems for producing modulated light are provided. A representative optical system incorporates an electron emitter and a electrical-to-optical converter. The electron emitter is operative to produce electrons. The electrical-to-optical converter is operative to receive electrons and convert the electrons into light. The optical system modulates the light so that modulated light is emitted. Methods and other optical systems also are provided.

Abstract: An optical communication device includes a first photon source emitting a first beam modulated with information. The first beam intersects a thin metal film and engenders a first surface plasmon wave thereon. Part of the first beam reflects from the metal film to form a reflected beam. A polarization structure rotates the polarization of the reflected beam. A reflecting structure reflects the reflected beam to form a second beam propagating back toward the film, which beam passes through the polarization structure again. On the metal film, the second beam engenders a second surface plasmon wave. Interaction between the first and second surface plasmon waves creates a surface plasmon standing wave. A second source provides a third beam intersecting the first and second beams at the metal film. Interaction between the third beam and the surface plasmon standing wave modulates the third beam as it passes through the metal film.

Abstract: A method is provided for detecting one or more substances. An optical path switch divides sample path radiation into a time series of alternating first polarized components and second polarized components. The first polarized components are transmitted along a first optical path and the second polarized components along a second optical path. A first gasless optical filter train filters the first polarized components to isolate at least a first wavelength band thereby generating first filtered radiation. A second gasless optical filter train filters the second polarized components to isolate at least a second wavelength band thereby generating second filtered radiation. The first wavelength band and second wavelength band are unique. Further, spectral absorption of a substance of interest is different at the first wavelength band as compared to the second wavelength band. A beam combiner combines the first and second filtered radiation to form a combined beam of radiation.

Abstract: A printer (100) able to print in a plurality of output formats depending on width of media (160) loaded in the printer (100) is disclosed. The printer (100) provides high resolution and grayscale imaging capability for monochromatic applications. Illumination optics (11) receive a source light beam, from one or more LEDs, uniformize and polarize the beam and direct the beam through a polarization beamsplitter (50). The polarization beamsplitter (50) directs one polarization state of light to one or more LCD spatial light modulators (52), which modulate the polarization of the polarized beam to provide output exposure energy suitable for image marking on media (160). An optional sensor (234) allows printer (100) to automatically detect the width of a given type of media (160) in order to select from a set of compatible output format. Multiple segments of media (160) at the image plane (150) simultaneously.

Abstract: A method for modulating a polarization-multiplexed optical clock signal for an optical communication system is described. The method includes splitting a linearly polarized input optical clock signal having a clock rate into a first and a second linearly polarized optical signal. The first linearly polarized optical signal comprises a first polarization state and the second linearly polarized optical signal comprises a second polarization state. The first linearly polarized optical signal is delayed relative to the second linearly polarized optical signal. The first and the second linearly polarized optical signals are combined to generate the polarization-multiplexed optical clock signal for the optical communication system. The polarization-multiplexed optical clock signal is then modulated with a polarization-insensitive optical modulator to encode data on the polarization-multiplexed optical clock signal.

Abstract: A real-time optical compensating apparatus reduces the PMD in an optical fiber by determining the principal states of polarization of the optical fiber and delaying one principal state of polarization with respect to the other.

Abstract: A light receiving module and a light receiving method to reduce polarization dependence, used in evaluation of polarization characteristics of various optical parts. The light receiving module has an optical mechanism including a first light transmission plate and a second light transmission plate between a first lens and a second lens, and a light receiving element of the outside of the optical mechanism. The first light transmission plate is inclined at such an angle as to have the same value as polarization dependence due to the inclination of the light receiving surface of the light receiving element, and subsequently the first light transmission plate is rotated by 90° in relation to the optical axis.

Abstract: An optical modulation device which can facilitate a reduction in size of a device and prevent overheating of the optical modulation device, and a projection display device utilizing the optical modulation device are provided. In the optical modulation device, sapphire glasses are affixed to the light-incident side and the light-emitting side surfaces of liquid crystal panels which respectively modulates light of three colors of red, green, and blue emitted from a light source according to image information. Therefore, heat generated on optical modulation devices can be discharged, so that overheating of the optical modulation devices can be prevented, and a reduction in size can be achieved. In addition, since the sapphire glass is difficult to scratch, it becomes easy-to-handle, thereby facilitating the management of the optical modulation devices.

Abstract: Electro-optic elements are formed in metal oxide films, such as lithium niobate, on a substrate such as lithium niobate for utilization in electro-optical devices. The electro-optic elements include trenches in the lithium niobate selected to improve the performance of the device. Traveling wave modulators may be formed with a waveguide having first and second arms, electrodes over the lithium niobate layer, and trenches formed in the layer to focus the electric field in the waveguide, resulting in improved modulator performance.

Abstract: In a projection display that includes a polarization beam splitter prism and two reflective light valves, each of a pair of dichroic beam splitters is disposed between the polarization beam splitter prism and a respective one of the reflective light valves. The arrangement as such ensures that only a minimal amount of light leakage components will reach a projection lens of the projection display so as to achieve optimum image quality.

Abstract: The present invention includes a polarization independent optical interconnect device for selectively interconnecting a plurality of optical signals between a plurality of inputs and a plurality of outputs. The present invention may provide advantages typically associated with conventional polarization based switches, including terabit per second data rates and high speed switching, to facilitate use in fiber optic networks. Moreover, the switch of this invention is polarization independent, and therefore, may route either polarized or unpolarized light. Since both the input and output light may be unpolarized, the switch of this invention may have a high light efficiency (i.e. no losses associated with an input polarizer) and minimal insertion losses as compared to typical polarization based switches.

Abstract: In an optical phase modulator, a substrate has electro-optical effect. An optical waveguide is formed in a surface portion of the substrate. A phase modulation section is provided on an input side to change a refractive index of the optical waveguide for phase modulation to input light. An adjustment section is provided on an output side to change a refractive index of the optical waveguide for elimination of polarization dependency of the phase-modulated light. In this case, the refractive index change rate in the phase modulation section and the refractive index change rate in the adjustment section may have different signs each other.

Abstract: An optical system according to the present invention includes a beam polarization combiner for receiving first and second sets of input beams, and a reflective spatial light modulator having a plurality of individually activated modulating elements each corresponding to a respective one of the different wavelengths of the input beams. Each input beam is directed at a modulating element of corresponding wavelength with input beams of the first and second sets impinging upon the modulating element from respective first and second incoming paths. Each modulating element selectively changes the input beams such that the outgoing path for each reflected beam of each set is superimposed on the incoming path for the other set. The beam combiner receives the reflected sets of beams and directs them in different directions based upon their polarization. The optical system may be used in a wavelength selective switch or a dynamic spectral equalizer.

Abstract: A wavelength selective cross-connect switch for selectively switching wavelength-separated input channels between two optical input signals. The cross-connect switch includes two dispersive elements, where each dispersive element receives an optical input signal and disperses it into a plurality of wavelength-separated input channels. The cross-connect switch also includes a switching array mechanism, such as a micro-electro mechanical system (MEMS) shutter array, receiving the plurality of wavelength-separated input channels from each of the dispersive elements and operative for selectively switching one or more of the wavelength-separated input channels between the optical signals.

Abstract: A solid state device used to modulate the intensity of reflected or transmitted light by modulating with an external voltage the optical thickness of a thin film ferroelectric placed in an etalon cavity is disclosed. The device is constructed by selecting a generally planar supporting substrate, preferably silicon or sapphire in order to be compatible with silicon integrated circuits. A dielectric stack consisting of alternating layers of different index of refraction materials, also specifically selected to be compatible with later growth of the thin film ferroelectric, is deposited thereon to form a partially reflective and partially transmitting mirror, followed by a transparent electrically conductive layer. The thin film ferroelectric is deposited on the conductive layer, followed by a second transparent conductive layer and a second dielectric stack. Leads are connected to the conductive layers and in turn to a voltage generator.

Abstract: An optical modulator and an image projection display apparatus using it can reduce a size of a system and improve efficiency, by attaching a reflection plane on a nonlinear matter. The optical modulator in accordance with the present invention includes a nonlinear matter which is divided into predetermined regions having a direction of a polarization which is periodically reversed, an electrode which is joined with the upper and lower sides of the nonlinear matter, for applying an electric field to the polarization region at the lower portion of the nonlinear matter and a reflection plane which is joined to the rear surface of the nonlinear matter, for reflect an incident light to an incident region again.

Abstract: An apparatus and method for filtering an optical input is disclosed. In an illustrative embodiment, an optical input is split into polarization components along separate paths. The polarization components are then fed into a first electro-optic device that includes a set of electrodes across which a voltage is applied to adjust a wavelength transmission characteristic of the device. A section of the first device positioned between the electrodes preferably has a birefringence that is adjusted depending on the voltage applied across the electrodes. The adjusted components of the optical input are thereafter combined to produce an optical output. Accordingly, the optical input can be attenuated based on the voltage applied to electrodes of the first electro-optic device.

Abstract: In the world of high speed communications where the use of return-to-zero modulation format is advantageous, there is a need for being able to exert electrical control, in a relatively simple manner, over the duty cycle of the optical pulses being generated without the undesirable effects of chirp, whilst providing good extinction between pulses. The invention proposes an optical pulse generator and methods of generating and shaping optical pulses using an arrangement of cascaded Mach-Zehnder type interferometers. The pulse generator has a signal generator that produces sinusoidal electrical modulation signals for application to the electrical inputs of cascaded Mach-Zehnder type interferometers. The first Mach-Zehnder type interferometer in the series is responsive to the sinusoidal electrical modulation signal being applied, to generate a series of optical pulses having controllable chirp.

Abstract: An optical device comprises a first birefringent crystal having a first length, a second birefringent crystal having a second length, and a dynamic polarization rotator. An optical signal propagating through the first and second birefringent crystals has an effective optical path length based, at least in part, upon the first length of the first birefringent crystal and the second length of the second birefringent crystal. The dynamic polarization rotator adjusts the effective optical path length of the optical signal in response to a control signal.

Abstract: An optical device comprises a first birefringent crystal having a first length, a second birefringent crystal having a second length, and a dynamic polarization rotator. An optical signal propagating through the first and second birefringent crystals has an effective optical path length based, at least in part, upon the first length of the first birefringent crystal and the second length of the second birefringent crystal. The dynamic polarization rotator adjusts the effective optical path length of the optical signal in response to a control signal.

Abstract: A polarization beam splitter comprises a substrate, two waveguides formed in the substrate for conducting different polarization components, and an evanescent coupler acting between the waveguides to split an input light signal incorporating TE and TM polarization components into an output signal consisting of the TE polarization component and an light output signal consisting of the TM polarization component conducted along respective waveguides. To this end the evanescent coupler comprises substantially identical adjacent portions of the two waveguides arranged symmetrically with respect to one another and having geometries such that one of the polarization components extends laterally within each waveguide portion to a greater extent than the other polarization component. The splitting apart of the two polarization components occurs due to the resulting difference between the coupling length for said one polarization component and the coupling length for said other polarization component.

Abstract: An electro-optical device is provided having an electro-optical panel and a case member, the electro-optical panel including a pair of substrates and a transparent member joined to at least one substrate of the pair of substrates, forming a structure which, in particular, allows the device to be made smaller and thinner, and the heat-dissipation capability to be increased in order to prevent overheating. A positioning section which accommodates one substrate of the pair of substrates, and which contacts an edge of the at least one substrate joined to the transparent member is provided in the case member accommodating the electro-optical panel.