Abstract: An optical interconnect includes a translatable optical source; an optical modulator element disposed on a circuit board and configured to receive an optical beam from the optical source; and an optical receiver disposed on a circuit board and configured to receive a modulated optical beam from the modulator element.

Abstract: The present invention relates to an acousto-optic device capable of extending the frequency band of SAWs being able to be generated by it, the acousto-optic device comprising: a light propagation unit for propagating light; a surface acoustic wave propagation unit capable of propagating a surface acoustic wave causing interaction with light which propagates in the light propagation unit; and a transducer electrode unit provided with a plurality of electrodes configured so as to correspond to a frequency band to be generated as the surface acoustic wave which propagates in the surface acoustic wave propagation unit.

Abstract: Multi-loop opto-electronic oscillators using tunable RF or microwave filters that achieve signal filtering in RF or microwave frequencies by optical filtering and signal tuning by optical tuning.

Abstract: A variable dispersion slope compensator with a high-accuracy and a low-cost structure for compensating the dispersion slope compensation error accompanying variations in the zero-dispersion wavelength in transmission fibers in long-distance, high-speed WDM (wavelength division multiplexing) transmission systems.

Abstract: A method and system is disclosed for making time alignment for a data transmission system. A first reference clock signal is provided to a first multiplexer coupled to a data modulator through a data driver, and a second reference clock signal is provided to a second multiplexer coupled to a clock modulator through a clock driver. Phase adjustment of the reference clock signal are conducted before the first reference clock signal is provided to the first multiplexer, wherein the phase adjustment aligns a timing of data modulated by the data modulator with a periodically modulated light source generated by the clock modulator.

Abstract: A cascaded modulator system (20) and method for a QKD system (10) is disclosed. The modulator system includes to modulators (M1 and M2) optically coupled in series. A parallel shift register (50) generates two-bit (i.e., binary) voltages (L1, L2). These voltage levels are adjusted by respective voltage adjusters (30-1 and 30-2) to generate weighted voltages (V1, V2) that drive the respective modulators. An electronic delay element (40) that matches the optical delay between modulators provides for modulator timing (gating). The net modulation (MNET) imparted to an optical signal (60) is the sum of the modulations imparted by the modulators. The modulator system provides four possible net modulations based only on binary voltage signals. This makes for faster and more efficient modulation in QKD systems and related optical systems when compared to using quad-level voltage signals to drive a single modulator.

Abstract: An optical fiber delivery system for delivering ultrashort optical pulses that can efficiently transmit high peak power, ultrashort optical pulses from an optical pulse source to a desired position in an optical apparatus is provided. An optical system including such an optical fiber delivery system is also provided. The optical fiber delivery system includes light waveguide means 20 for receiving high-pea power, ultrashort optical pulses and transmitting the optical pulses, negative group-velocity dispersion generation means 30 for providing negative group-velocity dispersion to the optical pulses transmitted through the light waveguide means 20, and an optical fiber 40 that transmits the optical pulses transmitted through the negative group-velocity dispersion generation means 30 along a desired distance. The incident ultrashort optical pulses that have been injected into the light waveguide means 20 are converted into down-chirped pulses.

Abstract: An integrated optical modulator and method for manufacturing thereof are disclosed. The integrated optical modulator comprises a carrier wave band modulator using a double sideband modulation method and an intermediate frequency band modulator using a single sideband modulation method. The carrier wave band modulator and the intermediate frequency band modulator are connected in series. A method for manufacturing an integrated optical modulator comprises preparing a substrate having at least one polarization reversed section, forming a first optical waveguide part and a second optical waveguide part on the substrate, forming a buffer layer over the first and second optical waveguide parts, forming sequentially a first electrode part and a second electrode part over the first optical waveguide part, and forming a third electrode part over the second optical waveguide part.

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: Methods for optical isolation in high peak power fiber-optic systems prevent damage to a facet within a fiber-optic isolator caused by back-reflected light from, for example, an optical amplifier. Preventing damage to the facet may include expanding a mode area of the back-reflected light and/or reducing a change in refractive index.

Abstract: A Mach-Zehnder optical modulator capable of feed-back compensating a change due to an optical coupling loss, and the characteristic change peculiar to functional devices, and a control method therefore, are provided. A control method for a semiconductor Mach-Zehnder optical modulator using a laser device as a light source includes modulating light emitted from the laser device, and extracting the light as output light; detecting monitor light separate from the output light, among the optically modulated light; and feed-back controlling an optical output intensity of the laser device based on the monitor light.

Abstract: A high-speed optical modulator constructed from a number of lower speed intensity modulators integrated onto a single optical chip.

Abstract: An optical phase modulator made of lithium niobate or the like phase-modulates the output light of a single-wavelength laser light source 20 that emits CW light, and the phase-modulated light is inputted to a dispersion medium 22. The positive chirp and negative chirp of light to which frequency chirp is applied by phase modulation draw near in the dispersion medium and an optical pulse is generated.

Abstract: The invention includes an optical signal transmission transducer. The optical signal transmission transducer includes a magnetic tunnel junction. The magnetic tunnel junction can be tuned to switch states in response to selected frequencies of a magnetic field. A light source can be modulated based upon states of the magnetic tunnel junction. An alternate embodiment of the optical signal transmission transducer includes a light transducer that generates magnetic sense signals based upon reception of modulated light signals. The light transducer can be integrated with a magnetic tunnel junction. The magnetic tunnel junction can be tuned to switch states in response to selected frequencies of the magnetic sense signal.

Abstract: The present invention relates to an optical modulator, divided into at least two active segments separated by at least one passive segment. The modulator comprises: an optical waveguide with an optical group index no having an optical signal propagating at an optical velocity vo, and a microwave transmission line with an electrical propagation index np, having an electrical signal propagating at an electrical velocity Ve. The electrical propagation index np of the unloaded microwave transmission line is lower than the optical group index no of the optical waveguide. The loading and length of the microwave transmission line are adjusted for a specific Bloch impedance and electrical velocity ve. The invention also relates to a method for adapting the impedance of an optical modulator.

Abstract: A Gires-Tournois etalon (GTE) (10) comprising an optical fibre (12) in which a primary chirped fibre Bragg grating (FBG) (16) is provided, an RF signal generator (20), a piezoelectric transducer (22), and a glass horn (24), for coupling an acoustic wave (26) into the fibre (12). The acoustic wave (26) causes a periodic compression within the fibre (12), which induces a low frequency periodic refractive index modulation within the grating section (14) of the fibre (12). This causes two side frequency components to be generated for each high-frequency component of the FBG (16). Two secondary grating are thus excited, having the same spectral bandwidth as the FBG (16), but a lower reflectivity and different central wavelengths. The free spectral range of the GTE (10) can be adjusted by varying the frequency of the acoustic wave (26). The reflectivity of the excited secondary gratings can be adjusted by adjusting the amplitude of the acoustic wave (26).

Abstract: An apparatus for inducing of the index of refraction of a substrate sensitive to electromagnetic radiation. The apparatus is capable of generating a first beam of electromagnetic radiation and a second beam of electromagnetic radiation that is different from the first beam. The first and the second beams converge toward a treatment area on the substrate, which is illuminated with electromagnetic radiation. The first beam and the second beam interact to create an interference pattern over a limited portion of the treatment area.

Abstract: Exemplary embodiments of the invention provide photonic crystal-based optical elements for integrated circuits. A photonic crystal optical device comprises a substrate and a plurality of pillars forming a photonic crystal structure over the substrate. The pillars are spaced apart from each other. Each pillar has a height and a horizontal cross-sectional shape. A material with a different dielectric constant than the pillars is provided within the spacing between the pillars. According to exemplary embodiments of the invention, the photonic crystal-based optical element can be an optical interconnect, a lens, or a filter. The photonic crystal-based optical element of the invention can be used to transmit solitons.

Abstract: The invention relates to an optical device, apt to generate and process optical codes at least one wavelength, comprising P inputs s, with 1?s?P, and P?1, and N outputs k, with 1?k?N and N?1, characterized in that it is apt to simultaneously generate and process Nc?2, made of C chips with time interval ?, with C?2, characterized in that the transfer function Tsk(f) from the input s to the output k satisfies the following formula: where: Fv is a transfer function of an optical filter, for v=0, 1 . . . , V?1, av is a constant value, for v=0, 1, . . . , V?1 Ssk is an integer number (Ssk?Z), Nk is a constant value, for k=2, . . . N, and V is a positive integer number with 1?V?log2N. The invention further relates to a set of optical codes, apt to be generated, in particular, by such optical device, and to networks and apparatus comprising such optical device.

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: Apparatus including a waveguide segment having a cladding that surrounds an optically-transmissive core extending along a path; a heater in thermal communication with the waveguide segment along at least a part of the path; a thermally-conductive substrate; a thermally-conductive base in fixed alignment with the waveguide segment and the thermally-conductive substrate, the thermally-conductive base being discontinuously on the waveguide segment along the path; and a rib in fixed alignment with the waveguide segment and the thermally-conductive substrate, the rib transversely extending in a direction away from the waveguide segment at a point along the path. Process utilizing apparatus for generating a phase shift in light.

Abstract: This invention pertains to a scene projection system and a method for projecting a scene that can simulate light temperature of above 2000 K. The system comprises of a light source part for generating light at a lower wavelength; a means part for individually controlling dynamic range, contrast, brightness, temporal characteristics and temporal dynamics of the light; a rare earth doped fiber part that re-emits the output light at a higher wavelength; and a means part for conveying light between its parts. The method comprises steps of generating light at a lower wavelength; individually controlling temporal characteristics, temporal dynamics, brightness and contrast of the light; passing the light through a rare earth-doped fiber; and re-emitting the light at a higher wavelength.

Abstract: A novel design for an optical differential quadrature phase shift keying (DQPSK) modulator comprises two intensity modulators in a three-arm interferometer.

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: 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 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 invention provides an optical signal noise suppressor and an optical signal noise suppressing method that can decrease noise components to be superimposed on signal light. The optical signal noise suppressor is a device for suppressing noise caused by SBS which is generated when a signal light propagates from a first end side to a second end side of an optical fiber, and comprises a light source section, an optical attenuator, an optical circulator and an optical isolator. A counter light, outputted from the light source section and passing through the optical attenuator, is guided into the optical fiber via the optical circulator. The counter light guided into the optical fiber is interrupted by the optical isolator, and does not reach the signal light source section.

Abstract: Super-resolution optical components and left-handed materials thereof are provided. A left-handed material includes a substrate, a plurality of deformed split ring resonators (DSRR), and a plurality of metallic bars, wherein the DSRR and the metallic bars are disposed on the substrate with each DSRR and metal bar alternately arranged.

Abstract: A photonic interconnect system avoids high capacitance electric interconnects by using optical signals to communicate data between devices. The system can provide massively parallel information output by mapping logical addresses to frequency bands, so that modulation of a selected frequency band can encode information for a specific location corresponding to the logical address. Wavelength-specific directional couplers, modulators, and detectors for the photonic interconnect system can be efficiently fabricated at defects in a photonic bandgap crystal. The interconnect system can be used for both classical and quantum information processing.

Abstract: An optical transmitter for converting and coupling an information-containing electrical signal with an optical fiber having an electrical input for coupling with an external electrical cable or information system device having a plurality of parallel data lines, a modulator for converting between an information-containing electrical signal on each data line and a multi-level digital pulse amplitude modulated signal corresponding to the binary electrical signal; and a signal timing circuit coupled to said modulator for aligning the data signal to a predetermined clock signal. The transmitter is preferably wavelength division multiplexed, using an electro-optical subassembly coupled to each respective timer circuit for converting between the information-containing electrical signal and a modulated optical signal corresponding to the electrical signal at a predetermined wavelength. The transceiver is preferably implemented in a pluggable standardized form factor.

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: 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: An optical waveguide element having a cladding layer formed on a substrate and at least one waveguide core formed in the cladding layer for transmitting an optical signal. Two heater sections are provided for shifting a phase of optical signals. The two heater sections show different design. This helps controlling heater induced birefringence.

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: The invention discloses an in-line polarization-state converter. In the polarization converter, a laser beam is radiated onto the side of a photosensitive optical fiber. The laser beam causes the refractive index of an optical fiber core to asymmetrically vary. Birefringence is induced in a core mode of the optical fiber by the variation in the asymmetrical refractive index. An optical fiber segment having the birefringence is generally disposed on a waveguide path of the optical fiber to change the polarization state of an optical signal passing through the optical fiber segment. That is, the phase of the optical signal passing through the optical fiber is changed by radiation of laser beams, which results in a variation in polarization state. The polarization converter disposed on the waveguide path is covered with a metal tube in order to prevent the polarization converter from being bent or broken.

Abstract: An electromagnetically responsive element includes sets of arrangements of self-resonant bodies, such as atoms or quantum dots that form an effective dielectric constant, typically at or near a resonance.

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 opto-electronic modulator includes a Mach-Zehnder structure that comprises p+in+-diodes in both arms of the Mach-Zehnder structure. The Mach-Zehnder structure is formed by waveguides so as to confine an optical mode in the opto-electronic modulator.

Abstract: Embodiments of a photonic link having low residual carrier, for use in transmitting information between an electronic signal source and an electronic signal receiver is provided. The photonic link comprises a transmitter, which uses angle modulation, and two threshold optical frequency discriminators that are biased to provide large even-order distortion, an optical signal receiver and at least one transmission fiber to transmit complementary modulated signals between the transmitter and the optical signal receiver, whereby the optical signal receiver reconstructs the complementary modulated signals into the electronic information for acceptance by the electronic signal receiver. Exemplary methods of transmitting information are also provided.

Abstract: This application describes coupled and non-coupled opto-electronic oscillators with enhanced performance. Coupled OEOs implement a dispersion compensation mechanism to reduce dispersion-induced optical loss, a polarization control mechanism to reduce polarization-dependent optical loss, or a combination of the dispersion compensation mechanism and the polarization control mechanism to enhance the oscillator performance.

Abstract: The present invention provides a light transmitter with a stable IQ amplitude ratio relative to the characteristic change of a modulating system. The QPSK light modulator of the present invention includes a laser light source for outputting light; an optical demultiplexer for inputting light and branching it in two directions; two optical phase modulators for inputting respectively one of the branched lights; a ?/2 phase shifter provided before or after one of the two optical phase modulators; an encoder for inputting I and Q signals into the optical phase modulators through drivers; and an optical multiplexer for synthesizing the outputs of the two optical phase modulators into a multiplexed, modulated light. The QPSK light modulator includes another optical demultiplexer after the optical multiplexer and a correcting section for correcting amplitude unbalance generated when light passes between the optical demultiplexers, by using output from the second optical demultiplexer.

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: An optical modulator using a thin plate capable of improving an S/N ratio of an output light is provided. The optical modulator including a thin plate 1 having an electrooptic effect and having a thickness of 20 ?m or less, an optical waveguide 4 formed on a top or bottom surface of the thin plate, and a modulation electrode formed on the top surface of the thin plate to modulate light passing through the optical waveguide, wherein a stray light removing member 10 is disposed within the thin plate or in a vicinity of the thin plate.

Abstract: The present invention provides systems and methods for measuring signal phase shift caused by changes in fiber length.

Abstract: Provided is a double waveguide electroabsorption modulator, in which two spot size converters are integrated between first and second optical waveguides, thereby reducing an insertion loss between an optical fiber and an optical modulator while favorably operating even in high input optical power. Therefore, the electroabsorption modulator can stably operate in higher input optical power while reducing an optical coupling loss and an optical confinement factor (OCF).

Abstract: Embodiments of a photonic link having low residual carrier, for use in transmitting information between an electronic signal source and an electronic signal receiver are provided. One exemplary photonic link comprises a transmitter, which has two non-linear threshold electronic to optical converters that are biased to provide large even-order distortion, an optical signal receiver and at least one optical transmission path to transmit complementary modulated signals between the transmitter and the optical signal receiver, whereby the optical signal receiver reconstructs the complementary modulated signals into the electronic information for acceptance by the electronic signal receiver. Exemplary methods of transmitting information are also provided.

Abstract: A high-speed optical modulator constructed from a number of lower speed intensity modulators integrated onto a single optical chip.

Abstract: In an optical modulation device (10) having an electrical/optical interaction region (11), an electrical signal line (3) is connected to an electrical signal input terminal (2a), another electrical signal line (4a) is connected to an electrical signal output terminal (2b), and a reflection control circuit (5) is connected to the other electrical signal line (4a). This reflection control circuit (5) is an impedance element which positively reflects an output electrical signal from the interaction region (11) of the optical modulation device (10). This makes it possible to raise the upper-limiting frequency at which the E/O (Electrical-to-Optical) response characteristic can be improved, and improve the flatness of the frequency characteristic of the E/O response without deteriorating the absolute value of the E/O response.

Abstract: A light-emitting element includes a light amplification unit and an external resonator. The light amplification unit has a function of amplifying light. The external resonator is connected to the light amplification unit. The external resonator includes a planar light waveguide and a stress application unit. The planar light waveguide is arranged inside the external resonator. The stress application unit applies stress directly or indirectly to at least a partial region of the planar light waveguide.