Abstract: A radio frequency (RF) to optical converter for RF imaging, wherein the converter comprises an array of RF antenna pixels adapted to receive RF signals, wherein the RF antenna pixels are adapted to facilitate RF resonance of the received RF signals; a photonic band gap (PBG) layer connected to the array of RF antenna pixels, the PBG layer comprising at least two materials, arranged in a photonic crystal (PC), wherein at least one of the materials comprises an electro-optic (EO) material, wherein the EO material is adapted to use the RF resonant signals to produce changes in optical properties of the EO material, and wherein the PC is adapted to use changes in optical properties of the EO material to produce enhanced changes in optical properties of the PBG layer; and an RF ground plane connected to the PBG layer.

Abstract: A method and apparatus for filter spectrum deconvolution and reshaping include providing a filter output of a spectrum signal and determining the intensity and wavelength of the spectrum signal at each spectral peak. The filter output is characterized as an integral of convolution of a spectrum signal function and a filter function. Transformation are then performed on the filter output to deconvolve and remove the undesirable filter function and add a desirable filter function to reshape the output filter spectrum.

Abstract: Invention discloses an apparatus that provides linear optical modulation of light carrier signals by an electrical modulation signal. Linearized modulation is achieved through the selection of a spacing profile between two optical transmission waveguides. The spacing profile relates to a transfer function, the parameters of which are chosen to yield linear modulation within a particular dynamic range. A preferred embodiment discloses the invention being fabricated within a monolithic structure.

Abstract: Various embodiments provide an apparatus and a method for operating the apparatus. The apparatus, in one embodiment, may include an optical waveguide located over a substrate, the optical waveguide having a first segment and a second segment. The apparatus may further include a single heating element configured to heat both the first segment and the second segment, wherein a light propagation direction at a point in the second segment differs by at least 90 degrees with respect to a light propagation direction at the point in the first segment.

Abstract: A modulator including a waveguide propagating an electromagnetic wave of given wavelength (?) with absorption. Means such as an electrical junction enable the residence time of the electromagnetic wave in the guide to be modified. A corresponding modulation method is also provided.

Abstract: An optical modulator of the Mach-Zehnder type including electrodes disposed above a substrate having a pair of linear portions of an optical waveguide includes a signal electrode to which modulating signals are applied; first and second earth electrodes; and a bias electrode to which a bias signal for controlling an operating point of the modulating signals is applied. The earth electrodes are disposed at either side of the signal electrode disposed above one of the linear portion, and the first earth electrode is disposed above the other linear portion. The bias electrode is disposed adjacent to the first earth electrode on a side opposite to the signal electrode. The bias electrode is disposed on a surface of the substrate, and a buffer layer is formed on the bias electrode. The first earth electrode has a ladder shape having the bias electrode interposed between the two long portions of the ladder.

Abstract: The present photonic RF generation and distribution system provides a system and method for distributing an RF output signal. The photonic RF distribution system includes two optical sources for generating optical signals. A first optical source (42) is operable to generate a first optical signal having an operating frequency. A second optical source (44) is operable to generate a second optical signal having an operating frequency. A modulator (46) is operable to impress an RF modulation signal on a tapped portion of the first optical signal such that a modulated signal is generated. A first coupler (52) combines the modulated signal with a tapped portion of the second optical signal, thereby forming a combined signal having a difference frequency component. A control photodetector (50) is responsive to the combined signal to generate a tone signal.

Abstract: The wavelength converter comprises (1) an optical multiplexer for multiplexing an amplitude-modulated first light and reference light, which is continuous light having a wavelength different from the wavelength of the first light, (2) an optical fiber for propagating the multiplexed light therethrough to generate a third light by a non-linear optical phenomenon, and (3) an optical filter having a pass wavelength range set such that a pulse time width of the third light is 20% or more narrower than a pulse time width of the first light after the third light has passed through the optical filter, or (3?) an optical filter having a pass wavelength range set such that a cross point of an eye pattern of the third light is lower than a cross point of an eye pattern of the first light after the third light has passed through the optical filter.

Abstract: A tunable dispersion compensator in which a heater portion can be easily constructed to reduce cost. A tunable dispersion compensator includes: an optical fiber having a grating portion; a heating unit for heating the grating portion to apply a temperature distribution to the grating portion; and a control unit for controlling the temperature distribution applied by the heating unit to control the group delay time characteristic of the grating portion. The heating unit includes: a heater including a single conductor having electrical resistors and which extends in a longitudinal direction of the grating portion over at least the entire length of the grating portion; and wirings electrically connected with the heater in respective positions along the longitudinal direction. The control unit supplies a voltage to each of the wirings.

Abstract: All optical clock recovery includes a transmitter for generating an optical timing signal. The transmitter includes a semiconductor laser for the production of a dynamically synchronizable timing signal, the laser having an external resonator for feedback of the timing signal to the laser, the feedback having a delay time greater than a relaxation oscillation time for the laser, and the laser outputting an optical timing signal having a characteristic dynamic. The transmitter supplies the optical timing signal to a receiver configured to receive the timing signal and to synchronize to the laser on receipt of the timing signal, such that the receiver outputs a recovered timing signal having the characteristic dynamic.

Abstract: A regenerator for restoring the originally encoded optical phase of a differential-phase-shift-keyed signal. In an embodiment, the regenerator simultaneously provides limiting amplification and reduces amplitude noise based on a phase-sensitive optical amplifier that combines a weak signal field of a degraded input data with a strong pump field supplied by a local oscillator in a nonlinear interferometer. The two fields interact through degenerate four-wave mixing, and optical energy is transferred from the pump to the signal and vice versa. The phase sensitive nature of the optical gain leads to amplification of a specific phase component of the signal, determined by the input pump-signal phase difference and the incident signal phase is restored to two distinct states, separated by 180° according to the original encoding. Simultaneously, gain saturation of the pump wave by the signal wave results in limiting amplification of the signal wave for removing signal amplitude noise.

Abstract: An optical bus interconnects two or more processors in a multiprocessor system. One or more electrical-to-optical (“E-O”) transmitters are optically coupled to the optical bus using optical couplers. The E-O transmitters receive electrical signals from the processors and convert the electrical signals to optical signals to be guided onto the optical bus. Optical-to-electrical (“O-E”) receivers are also coupled to the optical bus using the optical couplers. The O-E receivers receive optical signals from the optical bus and convert the optical signals to electrical signals for the processors.

Abstract: A method of filtering optical signals (300) utilizing an optical fiber (100A-100D). The method of filtering optical signals (300) includes the steps (304) selecting an optical fiber (100A-100D) coupled to a source of optical signals, (308) disposing a core (102) in the bore (103) of the optical fiber (100A-100D) formed of a core material (105), (308) selecting a core material (105) to provide a waveguide within the optical fiber (100A-100D), (310) disposing an optical grating (114-1) in a first optical cladding layer (104) disposed about the core (102), (312) propagating an optical signal within the optical fiber (100A-100D) guided substantially within the core (102), (314) modifying a propagation path of selected wavelengths comprising said optical signal with the optical grating (114-1), and (316) determining selected wavelengths for which the propagation path is modified by selectively varying an energetic stimulus to the core (102) thereby tuning the waveguide.

Abstract: An optical fiber (100A-100D) is provided with a cylindrical core (102) and a first optical cladding layer (104). The core (102) is formed of a core material (105) that is optically transmissive. The core material (105) has a core index of refraction that is continuously variable over a predetermined range of values responsive to a first energetic stimulus, such as thermal energy, photonic energy, magnetic field, and an electrical potential. The core (102) includes a bore (103) axially disposed within the first optical cladding layer (104). The bore (103) is filled with the core material (105). The first optical cladding layer (104) is disposed on the core (102). The first optical cladding layer (104) is formed of a photosensitive material. The photosensitive material has a first cladding layer index of refraction that is permanently selectively configurable responsive to an exposure to a second energetic stimulus. The first optical cladding layer (104) has gratings (114-1, 114-2) inscribed therein.

Abstract: A method for inspecting a grating biochip comprises the steps of irradiating a grating biochip using a light beam, measuring a diffracted light using a photodetector, selecting a plurality of parameters of the grating biochip, and optimizing the parameters to enhance the detection sensitivity, wherein the diffracted light is generated by the light beam passing the grating biochip. The grating biochip comprises a grating structure including a semiconductor substrate, a grating positioned on the semiconductor substrate and a dielectric layer covering the grating and the semiconductor substrate. The sample of the biochip is positioned on the grating structure.

Abstract: Provided is a tunable waveguide Bragg grating device, which includes: a waveguide through which incident light can travel; a Bragg grating formed in at least one region of the waveguide; and at least one thermal tuning unit formed at a position displaced from the central line of a waveguide core along the length direction of the waveguide core. Accordingly, it is possible to tune a reflection wavelength band and a group delay characteristic of the waveguide Bragg grating device in a variety of ways. It is also possible to manufacture a multiple channel tunable waveguide Bragg grating device with ease by applying an array arrangement, which is advantageous in constructing an integrated optical module.

Abstract: Methods and apparatus enable monitoring conditions in a well-bore using multiple cane-based sensors. The apparatus includes an array of cane-based Bragg grating sensors located in a single conduit for use in the well-bore. For some embodiments, each sensor is located at a different linear location along the conduit allowing for increased monitoring locations along the conduit.

Abstract: In one embodiment, an apparatus includes a passive element including one or more first waveguides and one or more second waveguides. The apparatus also includes an active element integrated into the passive element. The active element includes one or more third waveguides that actively guide light from the first waveguides to the second waveguides. The third waveguides include polarization-independent electro-optical (EO) thin film.

Abstract: Fuel injectors (10) for internal combustion engines are modified and equipped with fiber optic fuel pressure sensors (12) and fiber optic combustion pressure sensors (14). The combustion pressure sensors (14) are located in separate channels (26) formed in the fuel injectors with the lower portion (22) of the channels leading to the combustion chambers. Above the combustion pressure sensors (14) are fiber optic leads (24). In the preferred embodiments the sensors (46) are equipped with diaphragms (40) of novel shape (48) and employ multiple pairs of fibers (86, 88), temperature sensitive components (72, 74, 126) and novel compensation and status monitoring circuits (FIGS. 6, 9, 10, 14, 15, 18).

Abstract: An optical switch, an optical modulator, and a wavelength variable filter each have a simple configuration, which requires only a low driving voltage, which is independent of polarization, and which can operate at high speed. An optical switch includes a 3-dB coupler placed on an output, a 3-dB coupler placed on an output, and two optical waveguides connecting the input-side 3-dB coupler and the output-side 3-dB coupler together. The optical switch also includes a phase modulating section that applies electric fields to one or both of the two optical waveguides. At least two optical waveguides are a crystal material including KTaxNb1-xO3 (0<x<1) and KxLi1-xTayNb1-yO3 (0<x<1, 0<y<1), or KTaxNb1-xO3 or KxLi1-xTayNb1-yO3.

Abstract: An optical switch, an optical modulator, and a wavelength variable filter each have a simple configuration, which requires only a low driving voltage, which is independent of polarization, and which can operate at high speed. An optical switch includes a 3-dB coupler placed on an output, a 3-dB coupler placed on an output, and two optical waveguides connecting the input-side 3-dB coupler and the output-side 3-dB coupler together. The optical switch also includes a phase modulating section that applies electric fields to one or both of the two optical waveguides. At least two optical waveguides are a crystal material including KTaxNb1-xO3 (0<x<1) and KxLi1-xTayNb1-yO3 (0<x<1, 0<y<1), or KTaxNb1-xO3 or KxLi1-xTayNb1-yO3.

Abstract: An optical modulator includes a signal electrode for application of modulation signals whereby light propagated over an optical waveguide is modulated, and bias electrodes for application of a bias voltage for controlling an operating point for the modulation signals. A buffer layer is provided between a substrate exhibiting electro-optical effect and the bias electrodes, but at regions where no optical waveguide is formed beneath the bias electrodes, no buffer layer is provided, and the bias electrodes are provided directly upon the substrate. This configuration enables bias voltage to be reduced.

Abstract: Provided is a black matrix light guide screen display. In a particular embodiment, provided are a plurality of aligned light guides, each having an input end, a midsection and a magnifying output end. A black matrix material is disposed adjacent to the light guides proximate to the magnifying output ends. The plurality of aligned light guides are arranged into a plurality of light guide layers, each layer one light guide thick. The magnifying output ends of each layer are aligned in substantially contiguous parallel contact with interposed black spacers to provide substantially the same magnification vertically and horizontally.

Abstract: Various embodiments of the present invention are directed to photonic crystal switches. In one embodiment, a photonic crystal switch a photonic crystal switch includes a photonic-crystal-based light transmission layer that outputs an incident light beam in a selected, output direction. The photonic crystal switch may include two or more electrical contacts, positioned relative to the light transmission layer, to which a voltage is applied to select the output direction of the light beam.

Abstract: An optical device includes at least two photonic bandgap crystal (PBG) stacks that are each comprised of alternating layers of high and low index materials. A defect region is formed in a cavity region between the at least two photonic bandgap crystal stacks so as to provide the properties needed to reflect light received by the optical device.

Abstract: A wavelength selective switch device is disclosed that includes an elongated signal communication path extending from a first end of the device to a second end of the device. The signal communication path extends through a plurality of regions of varying indices of refraction, and the plurality of regions includes adjustable regions that are each coupled to an adjustable voltage source for changing a voltage potential across each of the adjustable regions such that the index of refraction of said adjustable regions may be changed by changing the voltage potential across each adjustable region.

Abstract: An optical signal optical path switching method comprising steps of using a thermal lens based on a distribution of refractive index produced reversibly caused by temperature increase generated in an area of the light-absorbing layer film of thermal lens forming devices 1, 2 and 3, that has absorbed control light beams 121, 122 and 123, and in the periphery thereof, causing the converged signal light beam to exit from the thermal lens forming device with an ordinary divergence angle when the control light beams 121, 122 and 123 have not been irradiated and no thermal lens has been formed, and causing the converged signal light beam to exit from the thermal lens forming device with a divergence angle larger than the ordinary divergence angle when the control light beams have been irradiated and a thermal lens has been formed, and causing the signal light beam to travel straight through holes 61, 62 and 63 of mirrors provided with the holes for the signal light beam to pass through when the control light beams

Abstract: The invention provides an optical switch including a substrate which has conductivity or semiconductivity, an optical waveguide layer which is formed on the substrate, and a control electrode which is formed on the optical waveguide layer. The optical waveguide layer includes an incident-side channel waveguide to which a light signal is incident and plural outgoing-side channel waveguides branched from the incident-side channel waveguide. The control electrode forms a reflection plane reflecting the incident light signal near a crossover portion of the plural outgoing-side channel waveguides by applying voltage to the optical waveguide layer with the substrate to control a refractive index of the optical waveguide layer, and switches propagation paths of the light signal.

Abstract: The present invention is concerned with 1×2 thermo-optic digital optical switches known in the art as “Y-branch digital optical switches” and variable optical attenuators.

Abstract: A fiber optic switch uses induced periodic variations in a multi-mode optic fiber, to control power loss in the switch and power output.

Abstract: An optical switching element comprising: a multimode waveguide having an electro-optical effect; one or a plurality of first single mode waveguides; a plurality of second single mode waveguides; a first electrode arranged in the vicinity of one edge on one side of the multimode waveguide; a second electrode arranged in the vicinity of the other edge on the same side of the multimode waveguide; and a third electrode arranged on the other side of the multimode waveguide, over the first electrode and the second electrode being arranged so as to be positioned on luminescent spots in an optical mode field generated by the light propagating through the multimode waveguide, and an optical path being switched between the first single mode waveguide and the second single mode waveguide by applying voltage between the first electrode and the third electrode and between the second electrode and the third electrode, is provided.

Abstract: A photonic-crystal electromagnetic-wave device includes a photonic crystal structure having a periodically changed optical property at least in one direction. The photonic crystal structure includes electromagnetic-wave absorptive portions periodically arranged, each of the absorptive portions having an extinction coefficient larger than that of the other portions of the photonic crystal structure.

Abstract: An integrated active electrical waveguide is described for optical waveguide modulators. The active waveguide may include an optical waveguide, a plurality of modulators integrated into the waveguide to modulate the index of refraction of the waveguide, and a plurality of local amplifiers, each coupled to a modulator.

Abstract: A variable light controlling device comprising a substrate, an optical waveguide disposed on the substrate, a first heater and a second heater to change the optical waveguide's temperature is fabricated. And a total amount of the power supplied to the first and the second heater, or a total amount of heat emitted from both of the first and second heater, is maintained substantially constant. Then, the substrate is protected from temperature changes, thereby, stable and quick wavelength tuning operations are realized.

Abstract: A photonic crystal may be configured to support a surface state for logic.

Abstract: A Mach-Zehnder type semiconductor device comprises electrodes for injecting carriers into first and second branch waveguides so as to change reflection indexes of the first and second branch waveguides. The device further includes electrodes which are placed above either one of the first or second branch waveguides or both of the first or second branch waveguides so as to remove the carriers. The Mach-Zehnder type semiconductor device can adjust a phase difference between first and second split lights transmitting through first and second branch waveguides, respectively, even if the lengths of the first and second branch waveguides are deviated from those designed values. The Mach-Zehnder type semiconductor device also can suppress optical loss of the first and second lights and generate an outgoing light without deterioration.

Abstract: A photonic crystal may be configured to support a surface state for logic.

Abstract: An optical deflector comprises a photonic crystal section, a light lead-in means for leading in light having a specific wavelength to the photonic crystal section and an external force application means for deforming the photonic crystal section by way of mechanical external force and changing the angle of refraction of the light led in by the light lead-in means in the photonic crystal section. Such an optical deflector has a compact configuration and operates at high speed.

Abstract: In order to provide a low-loss optical switch that is low in power consumption by providing the same as a self-holding type, and high speed and highly practicable, an optical switch of the present invention is composed of a quartz substrate (101), first and second input waveguides (102a and 102b), a first directional coupler (103), first and second arm waveguides (104a and 104b) of a Mach-Zehnder interferometric circuit, a second directional coupler (105), first and second output waveguides (106a and 106b), and a phase change material portion (100). A control light (for an amorphous to crystal transition) pulse (pulse width: 20 ns, pulse intensity: 5 mW) having a wavelength of 0.78 microns is irradiated. As a result of the control light pulse irradiation, the phase change material portion (109) changes in phase to a crystal state, and the optical switch transits to a bar condition.

Abstract: The invention relates to an electro-optic directional coupler suitable for use as a variable optical attenuator at reduced voltages compared to those known in the prior art. The present invention has found that by careful selection of an asymmetric directional coupler geometry, the transfer function of the device can be shifted so that it has an operating point between maximum and minimum transmission. Signal electrodes driven in push pull configuration advantageously use this operating point to achieve significant reduction in operating voltages for switching to maximum or minimum transmission. Asymmetry is created in the directional coupler by forming the waveguides to have different propagation constants by a difference in waveguide width, depth, index of refraction or index profile.

Abstract: An optical modulator of the invention includes a substrate having an optical waveguide and an electric waveguide formed therein, a driving circuit that generates a modulation electric signal, a relay circuit that gives the modulation electric signal to the electric waveguide via an electric filter circuit made of a capacitor and a resistor, and a terminal resistor that terminates the modulation electric signal that has propagated through the electric waveguide. The sum of the impedance of the electric filter circuit and the resistance of the terminal resistor is set to be substantially equal to the impedance of the driving circuit. Also, the resistance of the terminal resistor is set to be substantially equal to the characteristic impedance of the electric waveguide. Then, deterioration of the electric reflection characteristic in a low-frequency region can be restrained even if the frequency characteristic of the optical response is flattened and leveled by application of the electric filter circuit.

Abstract: The present invention provides a highly-integrated and compact optical element and further provides an optical element having various functions such as lower driving voltage, chirping suppression and polarization-independency. The optical element has a substrate 1 formed of a material having an electrooptic effect, a plurality of optical waveguides formed on the substrate, and a modulating electrode for applying electric field into the optical waveguides, and is characterized in that the modulating electrode has at least two branching and confluence lines on the same line for applying the same modulating signal into different optical waveguides.

Abstract: An apparatus and method for a switch for a radiation signal, the switch including a first waveguiding channel having a guiding region and one or more bounding regions coupled to the guiding region, the first waveguiding channel including a first lateral guiding port in a portion of the bounding regions, the lateral guiding port responsive to an attribute of radiation propagating in the channel to selectively pass a portion of the radiation therethrough; and an influencer, coupled to the first waveguiding channel, for controlling the attribute of the radiation.

Abstract: A device for transmitting modulated optical signals between a first unit and a second unit, in which the first unit is supported to be rotatable or movable linearly relative to the second unit, comprises a light guide extending along a given track on the first unit, a first light coupler for coupling light into and out of the light guide, and a second light coupler disposed on the second unit and movable relative to the light guide for coupling light into and out of the light guide. A coupling slide is provided for supporting the second light coupler, and is mechanically loosely connected to the second unit via a take-up unit so that the coupling slide is moved along the given track together with the second unit by a movement of the second unit.

Abstract: An optical mode converter comprising a slow wave electrode structure and including Schottky barriers for preventing an accumulation of free carriers in the optical waveguide region of the converter. The Schottky barriers are also used for suppressing higher order modes in the waveguide. Low refractive index insulators are used to allow efficient driving of the device without hindering the impedance or the microwave index of the optical mode converter. Two-photon absorption processes are eliminated through the use of a waveguide semiconductor material having a bandgap of at least twice the photon energy of the light beam propagating through the optical mode converter.

Abstract: A display element is provided with a light source and a waveguide that propagates a light emitted from the light source, wherein the light propagated in the waveguide is extracted to outside from a waveguide lateral face, and wherein the light is extracted out of the waveguide from the waveguide lateral face by changing a shape of the waveguide lateral face.

Abstract: Provided is a planar optical waveguide circuit type variable attenuator capable of light attenuation by an arbitrary value in a range from 0 to 10 dB and also by not less than 30 dB, which is small-sized and is of power saving type. The attenuator is composed of a Mach-Zehnder interferometer circuit 30 having input waveguides 1a, 1b and an output waveguide 1d which are formed on an optical waveguide layer 3, and comprises a slit 12 formed on the waveguide layer in a longitudinally intermediate part of at least one of the optical waveguides 1a, 1b, 1d and in a direction crossing the optical waveguides 1a, 1b, 1d, and matching medium displacing means 16a, 16b for displacing index-matching medium 13 in a part of the slit 12 from a position including a path of propagation light in the optical waveguides 1a, 1b, 1d, and a position retracted from the path of propagation light.

Abstract: Apparatuses and methods for forming displays are claimed. This invention relates to a display which may be conformal and which can receive information in order to alter or configure the display. In one embodiment, a flexible layer may be made to receive an array of blocks which drive a display material to provide an alterable or configurable display. This display is coupled to a receiver which receives data and drives the data onto the blocks causing the display to change. The receiver (and blocks) may be powered by a signal from a transmitter which beams the information to the receiver. The receiver in turn controls the update of the display information on the display. Another embodiment of the invention has a receiver coupled to each block. The receiver also may be independent from the block and may be deposited onto the flexible layer.

Abstract: An athermal arrayed-waveguide grating is disclosed and includes an input waveguide for inputting two or more optical signals from one exterior side, a grating array for separating the optical signals into different wavelengths of light, a first slab, formed with two layers and having different refractive indices from each other, for connecting the input waveguide with the grating array, a second slab for causing the different light wavelengths separated at the grating array to be imaged on an egress surface thereof, and an output waveguide array for outputting each light wavelength imaged on the egress surface of the second slab to the other exterior side in the form of a separated channel.

Abstract: An optical modulator structure includes a block that includes electro-optical (EO) materials. A waveguide and electrode structure is formed on a substrate. The block is in close proximity to the waveguide and electrode structure so as to form optical modulation when electric fields in the block are varied.