Abstract: A semiconductor electro-optical phase shifter may include a substrate, an optical waveguide segment (12) formed on the substrate, and first and second zones of opposite conductivity types configured to form a first bipolar junction perpendicular to the substrate. The phase shifter may also include a dynamic control structure configured to reverse bias the first junction and a static control structure configured to direct a quiescent current in the second zone, parallel to the first junction.

Abstract: An integrated circuit is described. This integrated circuit includes a ferroelectric layer disposed on top of the ring resonator, which has a resonance wavelength. The ferroelectric layer is positioned between electrical contacts. Moreover, there may be amorphous semiconductor materials between the electrical contacts and the ferroelectric layer. For example, the amorphous semiconductor materials may include: p-type amorphous silicon and/or n-type amorphous silicon. By applying a reverse-bias voltage across the electrical contacts, an electric field is generated in a plane approximately parallel to a top surface of the ring resonator. This electric field electro-optically tunes the resonance wavelength. The ring resonator may operate at low voltage and can be integrated with a silicon optical waveguide on a silicon-on-insulator (SOI) platform.

Abstract: An optical modulator includes a Mach-Zehnder optical waveguide that includes a pair of parallel waveguides, and a two-input-one-output optical coupler that couples light output from the parallel waveguides; a branching waveguide that branches a portion of light output from the optical coupler; and a light receiving unit that receives the light output from the branching waveguide. Orientation of an output end of the branching waveguide is angled toward the light receiving unit, to be oblique with respect to the parallel waveguides, and orientation of an output end of the optical coupler is angled toward a side opposite to that of the output end of the branching waveguide, to be oblique with respect to the parallel waveguides.

Abstract: A semiconductor electro-optical phase shifter may include an optical action zone configured to be inserted in an optical waveguide, and a bipolar transistor structure configured so that, in operation, collector current of the bipolar transistor structure crosses the optical action zone perpendicular to the axis of the optical waveguide.

Abstract: An electro-optic modulator includes a semiconductor substrate, a core region and slab regions. The core region is formed on the semiconductor substrate and includes a first low concentration doping region, a second low concentration doping region and a high concentration doping region formed between the first low concentration doping region and the second low concentration doping region. Slab regions are formed on the semiconductor substrate. The slab regions are in contact with the core region. A width of a depletion region included in the core region may be controlled based on a reverse bias voltage applied between the first low concentration doping region and the second low concentration doping region. If the width of a depletion region is controlled, an optical signal transmitted through the depletion region may be controlled. The electro-optic modulator according to example embodiments may increase an operation speed and decrease a power consumption of a system.

Abstract: An object of the invention is to provide an optical transmission apparatus capable of reducing the influence of nonlinear effect of an optical fiber, suppressing a band requested to a device from being widened, easily bias controlling a modulator, and flexibly switching plural modulation methods. An optical transmission apparatus 301 according to the invention includes a modulator 101 and a controller 102. The modulator 101 is a modulator capable of quadrapture phase-shift keying the light from a light source and outputting the light. The controller 102 controls the input signal to the modulator 101 and causes the modulator 101 to carry out a quadrapture phase-shift keying operation or a ?/2 shift binary phase-shift keying operation.

Abstract: In a new optical intensity modulator, a nonlinear change in refractive index is used to balance the nonlinearities in the optical transfer function in a way that leads to highly linear optical intensity modulation.

Abstract: In a bidirectional optical communications module, an optics system is provided having a lens block that uses a single surface for reflecting light into or reflecting light passing out of the end of the optical fiber and a single surface for reflecting light toward a monitor photodetector. No other surfaces in the lens block are used to turn the light path. A filter block of the optics system that is adjacent to the lens block performs wavelength multiplexing and demultiplexing. The filter block reflects light at either its lower or upper surface back toward the lens block. In some embodiments, a portion of light passes through the upper surface of the filter block to provide some attenuation of light being transmitted so that the light is not coupled back into the light source. Because the upper surface of the filter block is the topmost surface of the optics system, the optics system can be very compact while also limiting the number of surfaces that turn the light path.

Abstract: An light input/output unit has at least three first ports, including a first input port for inputting light and a first output port for outputting light; at least three second ports, including a second input port for inputting light and a second output port for outputting light; and an alignment port for inputting and outputting alignment light. An optical axis of the input/output light of the first port and an optical axis of the input/output light of the second port differ from each other. The dispersive element changes the optical axes of input/output lights of the first and second ports by an angle corresponding to a wavelength. The light deflective element has a first part for directing the light from the first input port to the first output port and a second part for directing the light from the second input port to the second output port.

Abstract: Methods and apparatus are disclosed for wirelessly communicating among integrated circuits and/or functional modules within the integrated circuits. A semiconductor device fabrication operation uses a predetermined sequence of photographic and/or chemical processing steps to form one or more functional modules onto a semiconductor substrate. The functional modules are coupled to an integrated waveguide that is formed onto the semiconductor substrate and/or attached thereto to form an integrated circuit. The functional modules communicate with each other as well as to other integrated circuits using a multiple access transmission scheme via the integrated waveguide. One or more integrated circuits may be coupled to an integrated circuit carrier to form Multichip Module. The Multichip Module may be coupled to a semiconductor package to form a packaged integrated circuit.

Abstract: An optical modulator may include a leftmost waveguide, a rightmost waveguide, and a dielectric layer disposed therebetween. In one embodiment, the waveguides may be disposed on the same plane. When a voltage potential is created between the rightmost and leftmost waveguides, these layers form a silicon-insulator-silicon capacitor (also referred to as SISCAP) structure that provides efficient, high-speed optical modulation of an optical signal passing through the modulator. As opposed to a horizontal SISCAP structure where the dielectric layer is disposed between upper and lower waveguides, arranging the dielectric layer between waveguides disposed on the same plane results in a vertical SISCAP structure. In one embodiment, the leftmost and rightmost waveguide are both made from crystalline silicon.

Abstract: A Mach-Zehnder (MZ) modulator made of semiconductor material and a method to drive the MZ-modulator are disclosed. The MZ-modulator includes a pair of arms to vary the phase of the optical beam propagating therein. One of the arms further provides the phase presetter that varies the phase of the optical beam by ?. The arms are driven by modulation signals complementary to each other but with the DC bias equal to each other.

Abstract: A device, such as a silicon modulator, in accordance with the present disclosure employs PN diodes without sacrificing the modulation depth, while achieving lower loss and better impedance matching to 50-Ohm drivers. In one embodiment, the device includes an input waveguide, an input optical splitter coupled to the input waveguide, first and second optical phase shifters coupled to the input optical splitter, an output optical splitter coupled to the first and second phase shifters, and an output waveguide coupled to the output optical splitter. The phase shifters are designed with variant capacitance per unit length.

Abstract: A low-voltage optical modulator includes a substrate, a waveguide, a first pair of electrodes, and a second pair of electrodes. The waveguide is diffused into the top surface of the substrate, into a major branch and a parallel modulating branch. A structure of the first and second pair of electrodes are same. The first pair of electrodes includes a first and a second electrode parallel to each other. The first electrode is formed on the modulating branch and the second electrode is opposite to the modulating branch and away from the major branch. The second pair of electrodes includes parallel third and fourth electrodes. The third electrode is formed on the major branch. The fourth electrode is opposite to the major branch and away from the modulating branch.

Abstract: This disclosure is directed to an optical transmitter arrangement 100 and a method therein producing a first RF-signal UA1 comprising a first set of data A1 carried by a subcarrier fC1, and a second RF-signal UB1 comprising a second set of data B1 carried by the subcarrier fC1. Further producing a first transform signal H(UA1) being a Hilbert Transform of the first RF-signal UA1, and a second transform signal ?H(UB1) being a Hilbert Transform of the second RF-signal UB1. In addition, modulating the optical carrier fopt with the first RF-signal UA1 and the first transform signal H(UA1), and forming a first sideband SB1 comprising the first set of data A1 at one side of the frequency f0 of the optical carrier fopt. In addition, modulating the optical carrier fopt with the second RF-signal UB1 and the second transform signal ?H(UB1), and forming a second sideband SB2 comprising the second set of data B1 at the other side of the frequency f0 of the optical carrier fopt.

Abstract: The optical modulator includes optical modulation units. The plurality of optical modulation units is disposed in parallel on the same substrate. One input waveguide branches off to be connected to the Mach-Zehnder type optical waveguide of each optical modulation unit, and an entire optical waveguide is formed such that outputs from the Mach-Zehnder type optical waveguides are combined and output through one output waveguide. A modulation signal with the same intensity is applied to a modulation electrode of each optical modulation unit. In at least some of the optical modulation units, mechanical structures including the modulation electrodes of the optical modulation units are configured such that an amplitude value of an optical output modulated by the modulation signal of the optical modulation unit is ½n (n is a natural number) of a maximum amplitude value in other optical modulation units.

Abstract: A ridge waveguide structure includes a substrate having a top surface; a ridge structure protruding from the top surface; and a waveguide formed in the ridge structure and a shape of the waveguide is corresponding to a shape of the ridge structure; the ridge structure includes a Y-shaped input section and a Y-shaped output section, the Y-shaped input section includes a total input section, a first branch and a second branch, the first branch and the second branch are diverged from the total input section and converged into the Y-shaped output section. The relation also relates to an electro-optic modulator.

Abstract: A semiconductor electro-optical phase shifter may include a first optical action zone having a minimum doping level, a first lateral zone and a central zone flanking the first optical action zone along a first axis, doped respectively at first and second conductivity types so as to form a P-I-N junction between the first lateral zone and the central zone. The phase shifter may include a second optical action zone having a threshold doping level, and a second lateral zone flanking the second optical action zone with the central zone along the first axis doped at the first conductivity type so as to form a P-I-N junction between the second lateral zone and the central zone.

Abstract: Waveguide-type optical phase modulator regions of a linear accelerator-type column electrode structure MZ optical modulator are arranged on a semiconductor optical waveguide. A transmission line of an integrated circuit receives a clock signal through a buffer circuit disposed on an input side. Clock terminators are connected between an end of the transmission line and clock terminator power supply electrodes (VCa, VCb). Individual driving circuits receive the clock signal from different positions of the transmission line. An i (1?i?m, i is an integer)-th individual driving circuit counted from the input side outputs a signal obtained by amplifying a digital input signal in synchronization with the clock signal to an i-th waveguide-type optical phase modulator region.

Abstract: Methods and apparatus are disclosed for wirelessly communicating among integrated circuits and/or functional modules within the integrated circuits. A semiconductor device fabrication operation uses a predetermined sequence of photographic and/or chemical processing steps to form one or more functional modules onto a semiconductor substrate. The functional modules are coupled to an integrated waveguide that is formed onto the semiconductor substrate and/or attached thereto to form an integrated circuit. The functional modules communicate with each other as well as to other integrated circuits using a multiple access transmission scheme via the integrated waveguide. One or more integrated circuits may be coupled to an integrated circuit carrier to form Multichip Module. The Multichip Module may be coupled to a semiconductor package to form a packaged integrated circuit.

Abstract: A phase modulation apparatus has a light source outputting continuous light, two phase modulators, and an intensity modulator. The phase modulation apparatus is provided with an RZ phase modulation circuit, in which the phase modulators phase-modulate the continuous light from the light source with data signals input to the phase modulators and generate two phase modulation optical signals, a phase shifter shifts the phase of one phase modulation optical signal by ?/2, and an intensity modulator intensity-modulates a multiplexed signal, combined with the other phase modulation optical signal, with an input clock signal CLK to convert the signal into an RZ signal, and, thus, to output the RZ signal, and a phase control circuit which adjusts the phases of the phase modulation optical signals generated by the phase modulator of the RZ phase modulation circuit so that the output of the RZ phase modulation circuit is maximum.

Abstract: According to embodiments of the present invention, an optical modulator is provided. The optical modulator includes a depletion region comprising a junction between from a first conductivity type portion and a second conductivity type portion, a first intrinsic region, and a second intrinsic region, and wherein the depletion region is disposed between the first intrinsic region and the second intrinsic region.

Abstract: Provided is an optical element including an optical waveguide including a core formed from: a rib part; and a first and second slab parts sandwiching the rib part. The first slab part includes a P-type region, the second slab part includes an N-type region, the rib part includes a P-type region which is in contact with the P-type region provided in the first slab part, and an N-type region which is in contact with the N-type region provided in the second slab part. The rib part includes a top portion which is located above the first and second slab parts and includes an undoped region formed from at least one of an intrinsic region and a low-concentration doping region which is doped at a dopant concentration 1/10 or less of a dopant concentration in at least one of the adjacent P-type region and the adjacent N-type region.

Abstract: A semiconductor electro-optical phase shifter may include a central zone configured to be placed in an optical waveguide and doped at a first conductivity type, a first lateral zone adjacent a first face of the central region and doped at a second conductivity type, and a second lateral zone adjacent a second face of the central zone and doped at the second conductivity type.

Abstract: A method for manufacturing an optical fiber includes melting an end of a crystal material and drawing the molten end of the crystal material to form a crystal filament. Conductive paint is coated on two surface sections of the crystal filament to form internal positive and negative electrodes not electrically connected to each other. The crystal filament is placed into a heat resistant tube that is heated until an outer layer of the crystal filament melts and adheres to an inner periphery of the heat resistant tube, with a center of the crystal filament remaining as a solid core. Conductive paint is adhered to two ends of the crystal filament to form external positive and negative electrodes electrically connected to the internal positive and negative electrodes, respectively. The optical fiber thus formed can serve as a photoelectric optical fiber for transmission of current signals.

Abstract: A Mach-Zehnder optical modulator with a series push-pull traveling wave electrode uses a balanced coplanar stripline with lateral ground planes. Two signal electrodes extend along the center of the optical modulator adjacent and parallel to the optical waveguides in a series push-pull configuration. The ground planes run parallel to the signal electrodes, but are spaced laterally outward from the signal electrodes.

Abstract: A polarization control device includes a MMI device having primary-side and secondary-side end-faces; a first phase shifter optically coupled to a first port in the primary-side end-face; a first optical waveguide optically coupled via the first phase shifter to the first port in the primary-side end-face; a second optical waveguide optically coupled to a second port in the primary-side end-face; and a tapered waveguide optically coupled to a first port in the secondary-side end-face. The first and second ports in the primary-side end-face are located on first and second axes, respectively. The first port in the secondary-side end-face is located on a third axis located between the first and second axes. The first, second, and third axes extend in a direction from the primary-side end-face to the secondary-side end-face. The tapered waveguide has a width decreasing in a direction from one end to the other end of the tapered waveguide.

Abstract: A semiconductor optical modulator includes optical input and output portions; a plurality of Mach-Zehnder modulators, each including first and second waveguide arms having first and second modulation electrodes, respectively; an optical demultiplexer coupled between the optical input portion and the Mach-Zehnder modulators through an optical waveguide; an optical multiplexer coupled between the optical output portion and the Mach-Zehnder modulators; a plurality of electrical inputs; and a plurality of differential transmission lines electrically connecting the electrical inputs to the Mach-Zehnder modulators. The first modulation electrode and the second modulation electrode of at least one of the Mach-Zehnder modulators, one of the electrical inputs, and one of the differential transmission lines that connects such one electrical input to such one Mach-Zehnder modulator form an electrical circuit having a differential impedance in a range of 80? to 95?.

Abstract: An optical modulator according to the present invention includes an optical branching section having at least one beam splitter and a mirror and configured to branch input light, a lens configured to converge the respective lights branched in the optical branching section, a plurality of phase modulation sections each configured to perform phase modulation of each light which is input thereto through the lens, and an optical combining section configured to combine a plurality of phase-modulated lights which are output from the plurality of phase modulation sections, and output modulated signal light.

Abstract: A waveguide lens includes a substrate, a planar waveguide formed on the substrate and configured to couple with a laser light source that emits a laser beam into the planar waveguide along an optical axis, and a media grating film including two media gratings with a gap intervening therebetween. Each media grating is symmetrical about a widthwise central axis. Each widthwise central axis and the optical axis are substantially parallel with each other and cooperatively define a plane that is substantially perpendicular to the planar waveguide.

Abstract: This invention concerns real-time multi-impairment signal performance monitoring. In particular it concerns an optical device, for instance a monolithic integrated photonics chip, comprising a waveguide having an input region to receive a signal for characterization, and a narrow band CW laser signal. A non-linear waveguide region to mix the two received signals. More than one output region, each equipped with bandpass filters that extract respective discrete frequency bands of the RF spectrum of the mixed signals. And, also comprising (slow) power detectors to output the extracted discrete frequency banded signals.

Abstract: Embodiments of the invention describe a multi-segment optical waveguide that enables an optical modulator to be low-power and athermal by decreasing the device length needed for a given waveguide length. Embodiments of the invention describe an optical waveguide that is folded onto itself, and thus includes at least two sections. Thus, embodiments of the invention may decrease the device size of a modulator by at least around a factor of two if the device is folded twofold (device size may be further reduced if the modulator is folded threefold, four-fold, five-fold, etc.). Embodiments of the invention further enable the electrode length required to create the desired electro-optic effect for the multi-segment optical waveguide to be reduced. In embodiments of the invention, certain electrodes may be “shared” amongst the different segments of the waveguide, thereby reducing the power requirement and capacitance of a device having a waveguide of a given length.

Abstract: An electro-optical modulator with two electrodes as part of a transmission line of a first phase modulator and two electrodes as part of a transmission line of a second phase modulator included in two arms of a Mach-Zehnder-interferometer. An electrical controller applies a first electrical high-frequency-modulated voltage signals between the first and second electrodes and applies a second electrical high-frequency-modulated signals between the fourth and third electrodes. The electrical controller applies signals such that voltages applied to the first and fourth electrodes have substantially a same high-frequency content, and voltages applied to the second and third electrodes have substantially the same high-frequency content. In such configuration, a constant voltage offset is produced by either the voltages applied to the first and fourth electrodes or, the second and third electrodes. Thereby, cross-talk between electrodes, electrical losses, device size and fabrication costs may be reduced.

Abstract: Electrooptical cell, including, on a substrate (1), a layer of ferroelectric massive material (4), with an electrode (2) forming an earth plane, provided between the substrate (1) and the ferroelectric layer (4), another electrode (5), narrow, mounted opposite the first above the ferroelectric layer and grooves (6) made in the ferroelectric layer, on either side of the upper electrode (5).

Abstract: The invention relates to adaptive optics techniques applied to alter the modal structure of light propagating in an optical fiber. In particular the invention relates to altering the modal structure in a multimode beam propagating in a multimode fiber by lowering the number of higher modes. The method comprises combining a wavefront sensor and/or a power sensor with a phase control actuator and actuator control algorithms, to alter the phase structure of the beam thereby to eliminate higher modes. The corrected beam can be then effectively coupled into a smaller diameter fiber with minimum loss of energy and concentrated to smaller spot sizes limited by diffraction.

Abstract: In an embodiment, a delay line interferometer (DLI) multiplexer (MUX) includes a first stage and a second stage. The first stage includes a first DLI and a second DLI. The first DLI includes a first left input, a first right input, and a first output and has a free spectral range (FSR) that is about four times a nominal channel spacing. The second DLI includes a second left input, a second right input, and a second output and has an FSR that is about four times the nominal channel spacing. The second stage is coupled to the first stage and includes a third DLI. The third DLI includes a third left input optically coupled to the first output, a third right input optically coupled to the second output, and a third output. An FSR of the third DLI is about two times the nominal channel spacing.

Abstract: Embodiments of the present invention provide stable lithium niobate waveguide devices, and methods of making and using the same. A lithium niobate-based waveguide device may include a Z-cut lithium niobate substrate having upper and lower surfaces, an optical waveguide embedded within the lithium niobate substrate, a signal electrode disposed on the upper surface of lithium niobate substrate and parallel to the optical waveguide, guard electrodes disposed on the upper surface of the lithium niobate substrate and flanking but spaced apart from the signal electrode, and a conductive layer on the lower surface of the lithium niobate substrate, wherein the conductive layer serves as a common ground reference for the signal and guard electrodes.

Abstract: A system is provided, the system including at least one integrated optical circuit (IOC) formed from at least one material, and a support-structure configured to support the at least one IOC to couple light between other components. A performance of the at least one IOC is improved by treatment with at least one selected gas.

Abstract: A plasmonic phase modulator and a method of phase modulation employ modulation of surface plasmons. The plasmonic phase modulator includes a semiconductor substrate configured to provide a surface charge that forms a plasmonic channel at the substrate surface. The modulator further includes an electrode and an insulator between the electrode and the semiconductor substrate. The electrode is configured to provide an electric field that influences the surface charge. The electric field includes a bias field component and a modulation field component. The surface plasmon is supported within the plasmonic channel at an interface between the semiconductor substrate surface and the insulator. A phase of the surface plasmon in the plasmonic channel is modulated by changes in the electric field. The method includes propagating the surface plasmon in the plasmonic channel and varying the modulation field component to modulate the phase of the propagating surface plasmon.

Abstract: A planar optical waveguide device, includes: two input portions that are waveguides that have the same width, are parallel to each other, and have rectangular cross-sections; a wide portion that is a linear waveguide and is connected after the two input portions; a tapered portion that is connected after the wide portion and that is a multi-mode waveguide which has a tapered shape having a width decreasing gradually and through which at least TE1 propagates; and an output portion that is connected after the tapered portion and that is a multi-mode waveguide which has a rectangular cross-section and through which at least TE1 propagates. The planar optical waveguide device forms a high-order mode conversion combining element that outputs the TE0, which is input to the two input portions, as the TE1 from the output portion.

Abstract: An electro-optic modulator includes a substrate, a waveguide lens, a Y-shaped waveguide, and electrodes. The waveguide lens and the Y-shaped waveguide are formed in the substrate. The Y-shaped waveguide connects the waveguide lens and includes a first section dedicated for transmitting TE mode and a second section dedicated for transmitting TM mode. The electrodes are configured to modulate outputs of the waveguide lens, the first section, and the second section.

Abstract: A Mach-Zehnder optical modulator with a travelling wave electrode has a signal transmission line conductor (S) carrying an input electrical signal, and two ground transmission line conductors (G1 and G2) providing a return path for the electrical signal. The signal transmission line conductor is positioned between the first and second ground lines, and the first and second optical waveguide branches are positioned between the signal transmission line conductor and the first ground line. The modulator therefore has a GSG structure providing an asymmetrically-loaded configuration.

Abstract: A downsized, low-power electro-optical modulator that achieves reducing both of the additional resistance in the modulation portion and the optical loss each caused by electrodes at the same time is provided. The electro-optical modulator includes a rib waveguide formed by stacking a second semiconductor layer 9 having a different conductivity type from a first semiconductor layer 8 on the first semiconductor layer 8 via a dielectric film 11, and the semiconductor layers 8 and 9 are connectable to an external terminal via highly-doped portions 4 and 10, respectively. In a region in the vicinity of contact surfaces of the semiconductor layers 8 and 9 with the dielectric film 11, a free carrier is accumulated, removed, or inverted by an electrical signal from the external terminal, and whereby a concentration of the free carrier in an electric field region of an optical signal is modulated, so that a phase of the optical signal can be modulated.

Abstract: An object of the present invention is to realize an optical gate switch of a monolithic integration type which can avoid problems of losses caused by light coupling of a phase modulation unit to a interferometer optical circuit unit, and can be minimized by integration. The optical gate switch according to the present invention includes an optical waveguide wafer in which a quantum well having a phase modulation effect which is generated by an intersubband transition is set as a core layer; a Michelson interferometer formed on the optical waveguide wafer; and a variable light intensity attenuation unit adjusting a light balance of an interferometer in one of reflection side arms of the Michelson interferometer reflection.

Abstract: The optical frequency comb generating device having two optical modulation parts 41 and 42 independently modulating optical waves propagating in two branch waveguides and a phase regulator 43 controlling a phase difference between the optical waves includes amplitude adjusting means 22 for adjusting a voltage amplitude of the RF signal supplied to at least one of the optical modulation parts, monitoring means 21 for monitoring the intensity Pout of the output light beam, and a bias control circuit 20 that controls the amplitude adjusting means to change a difference in voltage amplitude between the RF signals supplied to each optical modulation part, that detects a variation of the output light beam corresponding to the variation of the difference in voltage amplitude from the output signal of the monitoring means, and that controls the phase regulator on the basis of the detection result to adjust the phase difference.

Abstract: An optical semiconductor device includes a laser oscillator on a semiconductor substrate; and an optical modulator on the semiconductor substrate. The laser oscillator includes a pair of reflecting mirrors at least one of which is a loop mirror, and the loop mirror includes a loop waveguide and a plurality of first ring resonators serially inserted in the loop waveguide. The optical modulator includes a plurality of second ring resonators connected in cascade along a modulator waveguide. A transmission band width of the first ring resonator is set greater than a transmission band width of the second ring resonator.

Abstract: A tunable Radio Frequency (RF) filter device includes a tunable optical source configured to generate an optical carrier signal, and a modulator coupled to the tunable optical source and configured to modulate the optical carrier signal with an RF input signal. The tunable RF filter device may also include first and second optical waveguides coupled to the modulator and having first and second dispersion slopes of opposite sign, and an optical-to-electrical converter coupled to the first and second optical waveguides and configured to generate an RF output signal with a frequency notch therein based upon the tunable optical source.

Abstract: An electro-optical phase shifter to be located in an optical waveguide may include a rib of a semiconductor material extending along a length of the optical waveguide and a control structure configured to modify a concentration of carriers in the rib according to a control voltage present between first and second control terminals of the phase shifter. The control structure may include a conductive layer covering a portion of the rib and electrically connected to a first of the control terminals. An insulating layer may be configured to electrically isolate the conductive layer from the rib.

Abstract: Stabilization of an injection locked optical frequency comb is achieved through polarization spectroscopy of an active laser cavity, eliminating optical PM sidebands inherent in previous stabilization methods. Optical SNR of 35 dB is achieved. A monolithic AlInGaAs quantum well Fabry-Prot laser injection locked to a passively mode-locked monolithic laser is presented here. The FP laser cavity can be used as a true linear interferometric intensity modulator for pulsed light.

Abstract: A modulating apparatus includes a branch that branches input light; a first modulating unit that modulates the phase of a first branch obtained by the branch; a second modulating unit that modulates a second branch obtained by the branch; a third modulating unit that is connected in series to the first modulating unit, transmits the first branch without branching the first branch, modulates the phase of light transmitted by controlling a refractive index of the light transmitted; a fourth modulating unit that is connected in series to the second modulating unit, transmits the second branch without branching the second branch, and modulates the phase of a light transmitted by controlling a refractive index of the light transmitted; and a coupler that couples the first branch modulated by the first and the third modulating units and the second branch modulated by the second and the fourth modulating units, at different intensities.