Abstract: A method of implementing optical deflection switching includes directing a tuning operation at a specific region of coupled optical resonators coupled to an input port, a first output port and a second output port, the coupled optical resonator including a plurality of cascaded unit cells; wherein the tuning operation interrupts a resonant coupling between one or more of the unit cells of the coupled resonators so as to cause an input optical signal from the input port to be directed from the first output port to the second output port.

Abstract: A novel electroabsorption modulator based on tuning the Fermi level relative to mid-gap states in a semiconductor. The modulator includes a semiconductor waveguide that has an input port and an output port. Between the input port and the output port is a section of the waveguide that functions as an electroabsorptive region. Adjacent to the electroabsorptive region are electrical contacts. In operation by adjusting voltages on the electrical contacts, the quasi-Fermi level in the electroabsorptive region of the semiconductor waveguide is brought above or below mid band-gap electronic states. As these states transition between occupancy and vacancy, the absorption coefficient for optical radiation in the electroabsorptive region of the semiconductor changes.

Abstract: Techniques are generally disclosed for optical devices that may be used to implement a variety of logic devices or other circuits by optical means. Example optical devices use a photodiode to alter the charge carrier concentration in a waveguide, thereby altering the index of refraction of the waveguide. The photodiode may be driven by an optical signal, which may be coupled to the photodiode through an optical waveguide. The optical signal may be configured to control the phase of coherent light coupled through the waveguide. A variety of logic devices and other circuits may be implemented by allowing the light coupled through the waveguide to constructively or destructively interfere with other coherent light.

Abstract: In a multilevel light intensity modulator of the invention, input light is branched into n (n is an integer of 2 or more), and respectively sent to n branching waveguides. On the branching waveguides are respectively provided MZI light modulating sections. The MZI light modulating sections branch the input light into two at a branching ratio different from 0.5:0.5, and respectively output a binary optical signal with a quenching ratio being deteriorated, by on/off driving with a binary electric signal. Then by coupling the light output from the MZI light modulating sections, an optical signal with the light intensity modulated to a 2n value not including the zero level is output. As a result quaternary or higher level light intensity modulation which does not include the zero level, can be realized by a practical configuration using a binary electric signal.

Abstract: The invention relates to a method for establishing a light beam (CLB) with substantially constant luminous intensity comprising the steps of establishing a light beam (LB) by means of a light source (SAL) and controlling an attenuation of said light beam (LB) on the basis of occurrences of luminous intensity peaks (IP) in said light beam (LB).

Abstract: Embodiments of the inventions described herein comprise a device and method for manipulating an optical beam. The method comprises propagating an optical beam through a waveguide in proximity to a resonant cavity and pumping the resonant cavity with sufficient optical power to induce non-linearities in the refractive index of the resonant cavity. The method further comprises tuning the resonant frequency band of the resonant cavity with a modulation signal such that the optical beam is manipulated in a useful way.

Abstract: Data to be sent are, in a data communication unit, first divided into electric signal packets by a data transmission/receipt control unit, whereby an electric signal sequence tag is added to each electric signal packet, then converted into optical packets by an optical signal transmitting unit, and transmitted through an optical signal path. At optical switch, the optical paths of the packets are switched to optical signal paths by the actions of optical destination tags that are respectively synchronized with optical packets and irradiated by an optical signal transmitting unit. At optical signal receiving units, the received optical packets are converted to electric signal packets, and reassembled to be original data according to the identification information on the reassembly sequence recorded in the sequence tag in an electric signal packet by data transmission/receipt control units, and distributed to client devices as electric signals.

Abstract: A polarization beam splitter-polarization rotator-polarization beam combiner optical structure comprising a pair of polarization rotators having a polarization beam splitter associated with the input ends of the two polarization rotators, and a polarization beam combiner associated with output ends of the two polarization rotators, and a method of purifying a light signal comprising TE and TM modes by disassociating the primary TE and TM modes from first order splitter and rotation error components.

Abstract: It is an object of the present invention to provide a DSB-SC system capable of suppressing a third order component. The DSB-SC modulation having high extinction ratio can be realized by adjusting the first order component, which is generated by applying a modulation signal (3fm), and the third order component, which is generated by applying a basic signal (fm), to have reversed phase and the same intensity level, and then by applying the first order component to the third order component, these two components cancel each other.

Abstract: A polarization beam splitter-polarization rotator-polarization beam combiner optical structure comprising a pair of polarization rotators having a polarization beam splitter associated with the input ends of the two polarization rotators, and a polarization beam combiner associated with output ends of the two polarization rotators, and a method of purifying a light signal comprising TE and TM modes by disassociating the primary TE and TM modes from first order splitter and rotation error components.

Abstract: A catheter with many fiber optic pressure sensors. The sensor diaphragm is formed from a wafer with a thin silicon layer and a silicon substrate layer separated by a silicon dioxide layer. A method includes masking and etching channels through the silicon substrate layer in a pattern of concentric circles to form a concentric circular etched channels and cylindrical unetched portions of the silicon substrate layer between the channels, exposing the silicon dioxide in the etched regions, and dissolving the exposed silicon dioxide to expose the crystalline silicon layer in the etched regions. The unetched cylindrical portion of the silicon substrate forms the diaphragm support element and the thin silicon layer forms the diaphragm. After applying a reflective coating to the exposed thin silicon layer, the support element face is adhered to the end face of a tubular housing, and a fiber optic probe is inserted in the tubular housing.

Abstract: An optical switch includes a microresonator comprising a plurality of nanoparticles. The microresonator is configured to receive signal light having a signal wavelength and to receive a pump pulse having a pump wavelength. At least a portion of the microresonator is responsive to the pump pulse by undergoing a refractive index change at the signal wavelength.

Abstract: An optical buffer device includes plural optical memory elements that are capable of holding light and an optical delay element. The plural optical memory elements are arranged on an optical path through which signal light and control light propagate in mutually opposite directions. Further, the optical delay element is disposed between the optical memory elements that are adjacent to each other. The optical delay element imparts different delays to the signal light and the control light. According to a preferred exemplary embodiment of this optical buffer device, each of the optical memory elements includes an optical waveguide through which the signal light and the control light propagate and an optical resonator that is disposed in proximity to this optical waveguide, and a coupling between the optical waveguide and the optical resonator is generated or cancelled depending on whether or not the control light is inputted.

Abstract: It is an objective to control the occurrence of the disorder of a far-field pattern and of an optical axial shift. A manufacturing method of a semiconductor laser device has the step for preparing a semiconductor substrate which has growth of a multi-layer including an active layer, the step for forming a mask over the growth of a multi-layer, and a step for forming a stripe-shaped ridge by dry etching and wet etching. A structure stacking a p-type AlGaInP layer, an etch-stop layer, a p-type Alx=0.7GaInP layer, a p-type Alx=0.6GaInP layer, a p-type GaAs layer, in order, over the active layer is taken in order to make the tailing part created in the dry etching process smaller by wet etching. The tailing part is composed of a p-type Alx=0.7GaInP layer including a high mixed crystal ratio of aluminum. Therefore, the p-type Alx=0.7GaInP layer is etched faster than the p-type Alx=0.

Abstract: An all-optical logic gates comprises a nonlinear element such as an optical resonator configured to receive optical input signals, at least one of which is amplitude-modulated to include data. The nonlinear element is configured in relation to the carrier frequency of the optical input signals to perform a logic operation based on the resonant frequency of the nonlinear element in relation to the carrier frequency. Based on the optical input signals, the nonlinear element generates an optical output signal having a binary logic level. A combining medium can be used to combine the optical input signals for discrimination by the nonlinear element to generate the optical output signal. Various embodiments include all-optical AND, NOT, NAND, NOR, OR, XOR, and XNOR gates and memory latch.

Abstract: Provided is a lighting apparatus capable of uniformly and efficiently lighting a spatial light modulator. The lighting apparatus includes: a light source for outputting laser light; a multimode optical fiber in which the laser light outputted from the light source propagates through an internal core whose lateral cross section is a substantially polygonal outer diameter shape; and spatial light modulator for producing an image with illumination light from the multimode optical fiber. In the lighting apparatus, the laser light is outputted from the light source and is propagated to the multimode optical fiber in which an outer diameter shape of the lateral cross section of the core is a substantially polygonal shape, whereby the spatial light modulator can be uniformly and efficiently lighted.

Abstract: Provided are a signal-quality evaluation device and a signal adjustment method which require shorter evaluation time and which have high flexibility of application. A signal quality evaluation device 100 includes an optical component 110 and an optical output detector 120. In the optical component 110, an output optical power Pout is a function of an input optical power Pin, and this function Pout(Pin) has at least one maximum point. The optical output detector 120 detects the time-average power of light output from the optical component 110.

Abstract: An optical module is configured with a combination of a single-mode oscillating light source and an optical filter. In this optical module, the single-mode oscillating light source outputs a single-mode, frequency-modulated signal. Further, the optical filter converts the frequency modulation to an amplitude modulation. And, the single-mode oscillating light source and the optical filter are packaged without active alignment on the same substrate. Accordingly, it is possible to realize an optical module in a simple and low-cost configuration by packaging the single-mode oscillating light source and the optical filter by passive alignment, without active alignment, on the same substrate, and by using a simple optical filter such as a waveguide ring resonator, which converts a frequency modulation to an amplitude modulation.

Abstract: This invention provides composite materials comprising nanostructures (e.g., nanowires, branched nanowires, nanotetrapods, nanocrystals, and nanoparticles). Methods and compositions for making such nanocomposites are also provided, as are articles comprising such composites. Waveguides and light concentrators comprising nanostructures (not necessarily as part of a nanocomposite) are additional features of the invention.

Abstract: An optical module includes: a light source; a variable transmissivity member that is disposed on a light path of light emitted from the light source with a spacing from the light source, the variable transmissivity member having transmissivity that increases as temperature rises; and an optical fiber that receives light that has been transmitted through the variable transmissivity member.

Abstract: Whispering-gallery-mode (WGM) optical resonators made of crystal materials to achieve high quality factors at or above 1010.

Abstract: An optical module includes a light source, a variable transmittance member disposed on a light path of output light from the light source distant from the light source, and a coupling section for coupling the output light from the light source via the variable transmittance member, wherein coupling efficiency as a ratio between intensity of the light from the light source and intensity of light to be coupled to the coupling section rises in conjunction with a rise in temperature.

Abstract: This invention provides composite materials comprising nanostructures (e.g., nanowires, branched nanowires, nanotetrapods, nanocrystals, and nanoparticles). Methods and compositions for making such nanocomposites are also provided, as are articles comprising such composites. Waveguides and light concentrators comprising nanostructures (not necessarily as part of a nanocomposite) are additional features of the invention.

Abstract: An optical circuit that converts a phase-modulated optical signal into intensity-modulated signal light in accordance with a phase, the optical circuit including a square mode distribution forming portion that forms a plurality of interfering signals each assuming a square mode shape, the interfering signals having respective phases shifted from each other by a certain angle, a light interference portion that creates a signal having a certain mode distribution, from the interfering signal, and that applies a Fourier transform to the signal having the certain mode distribution, and an output portion that has a plurality of waveguides each provided in correspondence with the phase and that outputs an optical signal that has been output from the light interference portion.

Abstract: In one general embodiment, a method for deflecting an optical signal input into a waveguide is provided. In operation, an optical input signal is propagated through a waveguide. Additionally, an optical control signal is applied to a mask positioned relative to the waveguide such that the application of the optical control signal to the mask is used to influence the optical input signal propagating in the waveguide. Furthermore, the deflected optical input signal output from the waveguide is detected in parallel on an array of detectors. In another general embodiment, a beam deflecting structure is provided for deflecting an optical signal input into a waveguide, the structure comprising at least one wave guiding layer for guiding an optical input signal and at least one masking layer including a pattern configured to influence characteristics of a material of the guiding layer when an optical control signal is passed through the masking layer in a direction of the guiding layer.

Abstract: A high speed optical analog/digital conversion process with a simple configuration, in which an optical-pulse branching delay multiplexer generates as many duplicates of each optical pulse as the predetermined number of bits by branching each optical pulse string obtained by sampling an input optical analog signal, and generates a temporally consecutive optical pulse string by multiplexing the duplicated optical pulses with a predetermined intensity difference and time difference. An optical encoder and an optical-threshold processing unit perform an encoding and a quantization of an optical pulse string, and output an optical digital signal corresponding to the optical analog signal.

Abstract: An optical transmission system which provides bandwidth restricted optical signal comprises an input terminal (10) for accepting an electrical binary signal, an amplifier (12) for amplifying said electrical binary signal to the level requested for operating an electrical-optical converter (16) such as a Mach Zehnder light modulator, a bandwidth restriction means (14) which is for instance a low pass filter for restricting bandwidth of said electrical binary signal, and an electrical-optical conversion means (16) such as a Mach Zehnder light modulator for converting electrical signal to optical signal. Because of the location of the low pass filter (14) between an output of the amplifier (12) and the Mach Zehnder light modulator (16), the amplifier (12) may operate in saturation region to provide high level output signal enough for operating the Mach Zehnder light modulator, and a signal shaped by the low pass filter (14) is applied to the Mach Zehnder light modulator (16) with excellent waveform.

Abstract: It is an object of the invention to realize an optical waveguide device having multiple functions or high performance, to improve the productivity of products, and to provide an optical waveguide device capable of suppressing deterioration of an operating characteristic of the optical waveguide device. An optical waveguide device includes: a thin plate 1 having a thickness of 20 ?m or less; and at least an optical waveguide 2 formed in the thin plate. The thin plate is bonded and fixed to a supporting substrate 5 with an adhesive 4 interposed therebetween, and a film having a higher refractive index than the thin plate and the adhesive is provided on a surface of the thin plate bonded and fixed to the supporting substrate so as to be in contact with or close to at least a part of the optical waveguide. Preferably, the thin plate is formed of a material having a nonlinear optical effect or an electro-optical effect.

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

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

Abstract: The present invention proposes a method for modulating refractive indices of optical fiber gratings, wherein the UV exposure on a least one assigned location of an optical fiber grating is divided into to two UV shots, and the intensities or phases of the two UV shots, which expose the location sequentially, are controlled to make the total exposure intensity of one assigned location maintained at a fixed value, whereby the interference fringes, which are created by a superposition of the two UV shots, have fixed phases and adjustable intensities, and whereby the dc index of the optical fiber grating maintains fixed and the ac index independently adjustable.

Abstract: An optical semiconductor device has a heater, an optical waveguide layer, a first electrode and a second electrode. The heater is provided on a first semiconductor region and has more than one heater segment coupled or separated to each other. The optical waveguide layer is provided in the first semiconductor region and receives heat from the heater. The first electrode is coupled to a connecting point of the heater segments adjacent to each other. The second electrodes are electrically common and are coupled to other ends of the heater segments in opposite side of the connecting point respectively.

Abstract: In one general embodiment, a method for deflecting an optical signal input into a waveguide is provided. In operation, an optical input signal is propagated through a waveguide. Additionally, an optical control signal is applied to a mask positioned relative to the waveguide such that the application of the optical control signal to the mask is used to influence the optical input signal propagating in the waveguide. Furthermore, the deflected optical input signal output from the waveguide is detected in parallel on an array of detectors. In another general embodiment, a beam deflecting structure is provided for deflecting an optical signal input into a waveguide, the structure comprising at least one wave guiding layer for guiding an optical input signal and at least one masking layer including a pattern configured to influence characteristics of a material of the guiding layer when an optical control signal is passed through the masking layer in a direction of the guiding layer.

Abstract: Provided are a method of adjusting a photonic bandgap of a photonic crystal, a method of manufacturing a reflective color filter using the same, and a display device including the reflective color filter. The method of adjusting a photonic bandgap of a photonic crystal includes forming the photonic crystal having a photonic bandgap on a substrate, and changing the photonic bandgap by irradiating light onto the photonic crystal. In addition, the display device includes a backlight, a transflective liquid crystal panel including liquid crystal cells sealed between first and second substrates. Each liquid crystal cell corresponding to a pixel includes a transmissive area and a reflective area. A transmissive color filter is formed on the first substrate, which faces the backlight, and a reflective color filter is formed on each reflective area.

Abstract: One embodiment includes a connector for an optical pathway. The connector includes a body formed, at least in part, with a temperature sensitive material having one or more light transmission characteristics that change based upon the temperature of the material.

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 wavelength converter for binary optical signals includes an interferometer structure (110) for generating an output signal by modulating a received local signal (LS) according to the modulation of a fUrther received first input signal (IS 1). When such interferometer structures (110) are operated in a standard mode it is known in the art to control the power of the input signal such that the extinction ratio of the output signal is kept minimal. The invention also controls the power of the input signals to achieve the minimal extinction ratio when the wavelength converter and in particular the interferometer structure (110) is operated in a differential mode receiving two input signals.

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

Abstract: An optically sampling device optically samples an optical analog signal using a sampled signal having a predetermined sampling frequency, and outputs control light having a pulse train of an optically sampled optical analog signal. A signal generating device generates a pulse train of signal light which is synchronized with the sampled signal. An optical encoding device optically encodes the pulse train of the signal light according to the control light, by using optical encoders each including nonlinear optical loop mirrors, and outputs pulse trains of optically encoded signal light from said optical encoders, respectively. An optically quantizing device performs optical threshold processing on the pulse trains of optically-encoded signal light to optically quantize them, by using at least one of optical threshold processors each of which is connected to each of said optical encoders and includes a nonlinear optical device, and outputs optically quantized pulse trains as optical digital signals.

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: Thermally tunable optical dispersion compensation (ODC) devices are disclosed. In one aspect, an ODC device may include multiple Gires-Tournois (G-T) etalons. The etalons may be optically coupled together. The etalons may compensate for optical dispersion by collectively delaying light. At least one of the G-T etalons may have a temperature dependent partial reflector. The ODC device may also include at least one thermal device to change the temperature of the G-T etalon having the temperature dependent partial reflector. Methods of making and using the ODC devices are also disclosed, as well as various systems including the ODC devices.

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

Abstract: Reflection means such as a mirror are provided on the output end of an optical fiber, and the input signal light and control light are returned to the optical fiber. Although the zero-dispersion wavelength of the optical fiber fluctuates in the longitudinal direction, if the length is relatively short, it is possible to manufacture a high yield of optical fibers, which monotonically changes the zero-dispersion wavelength. Therefore, a relatively short optical fiber with a monotonic zero-dispersion change can be used. Since the zero-dispersion change is monotonic and the optical fiber is short, the amount of change in the zero-dispersion wavelength is small and the bandwidth becomes broader when the control light is set at the position of the average zero-dispersion wavelength. Additionally, although the length of the optical fiber is short, the operating length is twice as long and thus the generation efficiency does not degrade.

Abstract: In an optical signal level control apparatus used in a WDM system, the amount of circuitry per wavelength is reduced. Optical power level is detected on the output side of a variable optical attenuator, and the amount of attenuation in the variable optical attenuator is adjusted so that the output level becomes equal to a constant value L1. At this time, if the detected level is lower than a threshold value Th0 or Th-d, it is determined that a signal off condition has occurred, and the amount of attenuation is set to a constant value A1. The amount of attenuation, A1, is chosen to be sufficiently larger than the amount of attenuation used in the output level constant control but small enough to be able to detect the restoration of the signal. When the amount of attenuation is being held at the constant value A1, if the output level is restored to a level higher than the threshold value Th0 or Th1 (Th1<Th-d), the output constant control is resumed.

Abstract: An optical transmission device includes an optical phase modulator and a signal generation function. The optical phase modulator is controlled, so that when the state of an intensity-modulated optical signal shifts from a first luminescent state, through a non-luminescent state, to a second luminescent state, the phase of the optical signal in the first luminescent state and the phase of the optical signal in the second luminescent state are inverted with respect to each other, or so that when the state of the intensity-modulated optical signal shifts from the first luminescent state, through two or more non-luminescent states, to a third luminescent state, the phase of the optical signal in the first luminescent state and the phase of the optical signal in the third luminescent state are inverted with respect to each other.

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: 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: 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.