Abstract: A reflective structure includes an input/output port and an optical splitter coupled to the input/output port. The optical splitter has a first branch and a second branch. The reflective structure also includes a first resonant cavity optically coupled to the first branch of the optical splitter. The first resonant cavity comprises a first set of reflectors and a first waveguide region disposed between the first set of reflectors. The reflective structures further includes a second resonant cavity optically coupled to the second branch of the optical splitter. The second resonant cavity comprises a second set of reflectors and a second waveguide region disposed between the second set of reflectors.

Abstract: A light control device with a reduced electric loss is provided which can suppress a phenomenon of electrically reflecting a high-frequency signal even when it employs a dielectric anisotropic substrate. A light control device includes a signal electrode formed on a dielectric anisotropic substrate and ground electrodes disposed with the signal electrode interposed therebetween. Here, the signal electrode includes at least two signal electrode portions disposed in directions in which the dielectric constant of the substrate is different from each other and a curved connecting portion connecting the at least two signal electrode portions. The connecting portion is configured so that the characteristic impedance in parts connected to the at least two signal electrode portions is equal to that of the corresponding signal electrode portion, and the characteristic impedance in the connecting portion between the at least two signal electrode portions continuously varies.

Abstract: A silicon-based optical modulator exhibiting improved modulation efficiency and control of “chirp” (i.e., time-varying optical phase) is provided by separately biasing a selected, first region of the modulating device (e.g., the polysilicon region, defined as the common node). In particular, the common node is biased to shift the voltage swing of the silicon-based optical modulator into its accumulation region, which exhibits a larger change in phase as a function of applied voltage (larger OMA) and improved extinction ratio. The response in the accumulation region is also relatively linear, allowing for the chirp to be more easily controlled. The electrical modulation input signal (and its inverse) are applied as separate inputs to the second region (e.g., the SOI region) of each arm of the modulator.

Abstract: A DP QPSK optical modulator includes an input port; an optical branching unit; an optical modulation unit having first through fourth Mach-Zehnder interferometers; a first phase-change unit connected to the third Mach-Zehnder interferometer; a second phase-change unit connected to the fourth Mach-Zehnder interferometer; an optical multiplexer; and a multimode interference coupler including a multimode interference waveguide, first through third input ports, and an output port having a taper-shaped waveguide. The first Mach-Zehnder interferometer is connected to the first input port. One end of the optical multiplexer is connected to the second Mach-Zehnder interferometer and the third Mach-Zehnder interferometer via the first phase change unit. The other end of the optical multiplexer is connected to the second input port. The fourth Mach-Zehnder interferometer is connected to the third input port via the second phase-change unit.

Abstract: A temperature control module and a support block are mounted on a metal stem. A dielectric substrate is mounted on a side surface of the support block. A support block is mounted on a cooling surface of the temperature control module. A dielectric substrate is mounted on a side surface of the support block. A semiconductor optical modulation element is mounted on the dielectric substrate. A lead pin and a signal line are connected through a bonding wire. The signal line and a signal conductor are connected through a bonding wire. The signal conductor and the semiconductor optical modulation element are connected through a bonding wire.

Abstract: A phase modulator may include a middle layer having a first refractive index, a first surrounding layer of material in contact with the middle layer and having a second refractive index, a second surrounding layer of material in contact with the middle layer and may having a third refractive index, a first electrode in electrical contact with the first surrounding layer, and a second electrode may be in electrical contact with the second surrounding layer. When no voltage is applied across the first electrode and the second electrode, the first refractive index may be greater than the second refractive index and the third refractive index. When a voltage is applied across the first electrode and the second electrode, the first refractive index may be less than the second refractive index within a portion of the phase modulator substantially within an electric field induced by such voltage.

Abstract: An improved algorithm for calculating multimode fiber system bandwidth which addresses both modal dispersion and chromatic dispersion effects is provided. The radial dependence of a laser transmitter emission spectrum is taken into account to assist in designing more effective optical transmission systems.

Abstract: An optical structure can include a nanocrystal on a surface of an optical waveguide in a manner to couple the nanocrystal to the optical field of light propagating through the optical waveguide to generate an emission from the nanocrystal.

Abstract: An arrayed waveguide grating optical multiplexer/demultiplexer according to the present invention including an input channel waveguide, an input slab waveguide, an arrayed waveguide, a polarization dependence eliminating means, an output slab waveguide, a temperature compensating means, and an output channel waveguide is characterized in that the temperature compensating means compensates for the temperature dependence of the optical path lengths in the channel waveguides of the arrayed waveguide, and the polarization dependence eliminating means eliminates the temperature dependence and the polarization dependence of the arrayed waveguide grating optical multiplexer/demultiplexer at the same time.

Abstract: A wavelength conversion structure includes a light guide formed of a light-transmissive member having a laser light incident port that allows the laser light to be introduced and a phosphor-containing layer that covers at least part of the surface of the light guide. The light guide has a light diffusing structure having asperities and a light reflecting film. The asperities are formed over the surface of the light guide except a laser light incident surface having the laser light incident port. The light reflecting film is formed over the surface of the light guide along the asperities except the laser light incident port and the portion covered with the phosphor-containing layer.

Abstract: During operation of an electro-absorption modulator, an optical signal is conveyed, using an optical waveguide in the electro-absorption modulator, to a semiconductor layer that substantially fills a gap between two portions of the optical waveguide. Then, the optical signal is electro-absorption modulated by selectively applying a voltage to electrodes that produces an electric field, approximately perpendicular to the midline of the optical waveguide, in the semiconductor layer. These electrodes are coupled to the edges of the semiconductor layer at the periphery along the width of the semiconductor layer by intervening layers. Furthermore, the intervening layers include a material that has a lower index of refraction than the semiconductor layer, and a lower optical absorption than the electrodes.

Abstract: A vital sign measurement device includes a sensor fixation device, a sensor frame, an optical sensing system, and an output unit. The sensor fixation device is adapted to be placed against an anatomical location of a subject. The optical sensing system includes an optical waveguide, an optical source device to supply optical energy to the optical waveguide, and an optical detector to detect an amount of optical energy exiting the optical waveguide. The optical sensing system is adapted to sense an arterial pulse from the compression or flexing of at least a portion of the optical waveguide resulting in reduction of the amount of light exiting the optical waveguide. The output unit is configured to receive a signal indicative of the amount of light exiting the optical waveguide and to generate a measure of the vital sign based at least in part on the received signal.

Abstract: A temperature control module and a support block are mounted on a metal stem. A dielectric substrate is mounted on a side surface of the support block. A support block is mounted on a cooling surface of the temperature control module. A dielectric substrate is mounted on a side surface of the support block. A semiconductor optical modulation element is mounted on the dielectric substrate. A lead pin and a signal line are connected through a bonding wire. The signal line and a signal conductor are connected through a bonding wire. The signal conductor and the semiconductor optical modulation element are connected through a bonding wire.

Abstract: Embodiments of the invention provide apparatuses and methods for phase correlated seeding of parametric mixer and for generating coherent frequency combs. The parametric mixer may use two phase-correlated optical waves with different carrier frequencies to generate new optical waves centered at frequencies differing from the input waves, while retaining the input wave coherent properties. In the case when parametric mixer is used to generate frequency combs with small frequency pitch, the phase correlation of the input (seed) waves can be achieved by electro-optical modulator and a single master laser. In the case when frequency comb possessing a frequency pitch that is larger than frequency modulation that can be affected by electro-optic modulator, the phase correlation of the input (seed) waves is achieved by combined use of an electro-optical modulator and injection locking to a single or multiple slave lasers.

Abstract: An optical device for generating a frequency comb includes an optical source and a first waveguide comprising a nonlinear optical medium operable to mix at least two input optical waves to generate a plurality of first optical waves. The optical device also includes a second waveguide concatenated to the first waveguide and characterized by a first dispersion characteristics and operable to compress the waveforms of the plurality of first optical waves and to reduce a frequency chirp introduced by the first waveguide. The optical device additionally includes a third waveguide concatenated to the second waveguide. The third waveguide comprises a nonlinear optical medium and is operable to mix the plurality of first optical waves to generate a plurality of second optical waves and to increase a total number of second optical waves with respect to a total number of first optical waves.

Abstract: The present invention discloses an ultra-compact optical modulator comprising at least one resonator on a semiconductor chip. The EO modulator modulates incoming light having a certain wavelength range and comprises a waveguide layer accommodating at least one resonator having a periodic complex refraction index distribution structure defining a periodic defect band-edge and a cladding layer; and at least one electrode; the waveguide layer, the cladding layer and the electrode forming a capacitor structure; such that when an external voltage is applied to the capacitor structure the free carrier concentration in the waveguide layer is controlled, enabling a modulation of the resonator's refractive index; wherein the periodic defect band-edge is selected to be within the wavelength range, enabling a slow-light propagation of the incoming light within the waveguide layer.

Abstract: Improved apparatus and method for collecting and directing light from a source via a light guide and modulated display assembly in an efficient manner through the design and use of prismatic optical structures, diffusers and/or light redirectors.

Abstract: An optical modulator includes a first graphene and a second graphene on an upper surface of a semiconductor layer, a first electrode on the first graphene, and a second electrode on the second graphene. Respective side surfaces of the first graphene and the second graphene are separated from each other. A first ridge portion of the semiconductor layer and a second ridge portion on the second graphene constitute an optical waveguide, and the first and second graphenes are on a center portion of the optical waveguide in a vertical direction to the semiconductor.

Abstract: A hybrid integrated module includes a semiconductor die mechanically coupled face-to-face to an integrated device in which the substrate has been removed. For example, the integrated circuit may include an optical waveguide that conveys an optical signal, which is fabricated on a silicon-on-insulator (SOI) wafer in which the back-side silicon substrate or handler has been completely removed. Moreover, an optical device may be disposed on the bottom surface of an oxide layer (such as a buried-oxide layer) in the integrated device, and the geometry and materials in the integrated device may be selected and/or defined so that the optical signal is evanescently coupled between the optical waveguide and the optical device.

Abstract: Exemplary apparatus and method can be availed for providing at least one electromagnetic radiation. For example, it is possible to provide at least one first electromagnetic radiation having a frequency that changes over time with a first characteristic period. Further, with at least one hardware arrangement, it is possible to receive and modify the first electromagnetic radiation(s) into at least one second electromagnetic radiation having a frequency that changes over time with a second characteristic period. The second characteristic period can be smaller than the first characteristic period. The hardware arrangement(s) can include a resonant cavity having a round-trip propagation time for the first electromagnetic radiation(s) that can be approximately the same as the first characteristic period.

Abstract: Provided is a semiconductor integrated circuit. The semiconductor integrated circuit includes a semiconductor pattern disposed on a substrate and including an optical waveguide part and a pair of recessed portions. The optical waveguide part has a thickness ranging from about 0.05 ?m to about 0.5 ?m. The recessed portions are disposed on both sides of the optical waveguide part and have a thinner thickness than the optical waveguide part. A first doped region and a second doped region are disposed in the recessed portions, respectively. The first and second doped regions are doped with a first conductive type dopant and a second conductive type dopant, respectively. An intrinsic region is formed in at least the optical waveguide part to contact the first and second doped regions.

Abstract: A leaky travelling wave array of optical elements provide a solar wavelength rectenna.

Abstract: An optical phase modulator based on the principles of stimulated Brillouin scattering is disclosed. The optical phase modulator uses a pump wave and a probe wave counte-propagating in an optical fiber, whose frequencies are chosen such that a difference thereof differs from a resonant Brillouin frequency of the optical fiber. The pump wave is amplitude modulated prior to injecting into the optical fiber, causing phase modulation of the probe wave inside and at the exit from the optical fiber. Alternatively, the probe wave can be amplitude modulated, thereby causing a phase modulation of the pump wave. In the embodiments of the invention, the pump wave is a continuous wave, and the probe wave is a pulse Stokes wave or an anti-Stokes wave. A corresponding optical network using the phase modulator is also disclosed.

Abstract: A Mach-Zehnder interferometer type optical modulator includes first and third optical waveguides; input and output optical couplers; and a phase shifting section disposed between the input and output optical couplers. The phase shifting section includes first and second optical waveguide structures each including an n-type semiconductor section, a core layer and a cladding layer. The cladding layer of the first optical waveguide structure includes a first section disposed on the core layer, and second and third sections disposed on the first section. The second and third sections are juxtaposed to each other in a direction that intersects a waveguiding direction. The first and second sections are composed of a p-type semiconductor, and the third section is composed of an undoped semiconductor.

Abstract: A semiconductor optical device includes a first optical waveguide including first, second, and third sections; a second optical waveguide including fourth, fifth, and sixth sections; an input optical coupler; and an output optical coupler. The first and second optical waveguides and the input and output optical couplers each include a first cladding layer composed of an n-type semiconductor and a core layer. The second and fifth sections each include an intermediate semiconductor layer on the core layer, and a second cladding layer composed of an n-type semiconductor. The first, third, fourth, and sixth sections and the input and output optical couplers each further include a third cladding layer on the core layer. At least one of the third cladding layers includes a first cladding section on the core layer and a second cladding section on the first cladding section. The second cladding section is composed of a semi-insulating semiconductor.

Abstract: An optoelectronic apparatus for controlling a signal includes an optical waveguide having a variable refractive index; an active device formed within the waveguide, the device having three electrodes, a drain, a source and a gate; and wherein the device is located within the waveguide so that current flowing from the drain to the source changes the refractive index.

Abstract: 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, including 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 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: An optical phase modulator includes a main Mach-Zehnder interferometer having first and second main optical waveguide path arms, whose initial phase difference in the used wavelength is ?, a first sub Mach-Zehnder interferometer having first and second sub optical waveguide path arms that are formed in the first main optical waveguide path arm, whose initial phase difference in the used wavelength is 0, and a second sub Mach-Zehnder interferometer having third and fourth sub optical waveguide path arms that are formed in the second main optical waveguide path arm, and whose initial phase difference in the used wavelength is 0. Of each of the main optical waveguide path arms and the sub optical waveguide path arms, at least the portions where high-frequency electrodes are formed are constructed using semiconductor waveguide paths, and reduce the effects of frequency chirping caused by an orthogonal component due to light absorption in the semiconductor.

Abstract: Included are a first modulator, a second modulator, a first optical amplifier that amplifies an output of the first modulator at an amplification factor based on a first bias signal, a second optical amplifier that amplifies an output of the second modulator at an amplification factor based on a second bias signal, an optical phase adjuster that phase-rotates an output of the second optical amplifier, an optical multiplexer that multiplexes an output of the first optical amplifier with an output of the optical phase adjuster, and a second bias corrector that generates a first pulse signal and a second pulse signal, which are complementary to each other, and obtains a first bias value and a second bias value based on a change of strength of an output signal of the optical multiplexer. The first and second pulse signals are superimposed on the first and second bias signals, respectively.

Abstract: 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, including 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 is provided on a surface of the thin plate bonded and fixed to the supporting substrate so as to be in contact with a part of the optical waveguide.

Abstract: An optical transmitter module includes a light source, a first optical circulation unit, a first optical reflector, and an output unit. The light source emits a first light signal with a first wavelength, and a second light signal with a second wavelength. The first optical circulation unit includes three optical couplers and three optical isolators, which are alternately connected to one another to form a loop. The first optical circulation unit includes a first port at a first optical coupler, a second port at a second optical coupler, and a third port at a third optical coupler. The first port is optically coupled to the light source. The first optical reflector is optically coupled to the second port. The first optical reflector reflects the first light signal back to the second port. The output unit is optically coupled to the third port to output the first light signal.

Abstract: A controllable optical ring resonator, a photonic system and a method of controlling an optical ring resonator employ control electrodes periodically spaced apart along a closed loop optical path of an optical waveguide. The controllable optical ring resonator includes the optical waveguide and a plurality of the periodically spaced control electrodes. The photonic system includes an input optical waveguide segment and the controllable optical ring resonator adjacent and optically coupled to the segment. The method includes providing the plurality of periodically spaced control electrodes, providing an optical signal within the optical path, and addressing one or more of the control electrodes to interact with the optical signal within the optical path.

Abstract: A waveguide structure includes core 1 formed of a semiconductor such as Si, two external regions 2 which are not optically connected to the core but arranged at a certain distance from the core and bridges 3 which electrically connect the external regions to the core. Light propagating in the waveguide core is strongly confined in the waveguide core and optically disconnected from (i.e. not coupled with) the external regions, so that light can propagate in the waveguide without being affected by the existence of the external regions. Furthermore, the waveguide core is electrically connected to the external regions through the bridges, so that a voltage can be applied and a current can be caused to flow to the core from the external regions.

Abstract: A method involving: providing an optical waveguide made of a semiconductor material and having a region that is doped by a deep level impurity which creates deep level states in a bandgap in the semiconductor material, the deep level states characterized by an occupancy; passing an optical signal through the optical waveguide and between the region doped by the deep level impurity; and modulating the occupancy of the deep level states to thereby modulate the optical signal.

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: An optical wavelength multiplexing/de-multiplexing circuit having a low loss and a flat transmission spectrum is provided. The optical wavelength multiplexing/de-multiplexing circuit compensates a temperature dependence of a center transmission wavelength which remains in an athermal AWG, and has an excellent accuracy of the center transmission wavelength in a whole operating temperature range or has a comparatively wide operable temperature range. The temperature dependence of the transmission wavelength in the athermal MZI is modulated and set so as to cancel the temperature dependence of the center wavelength which remains in the athermal AWG. The present invention focuses particularly on an optical coupler in the MZI and modulates the temperature dependence of the transmission wavelength in the MZI by providing the optical coupler itself with a mechanism which changes a phase difference between two outputs by temperature.

Abstract: A high speed silicon-based optical modulator with control of the dopant profiles in the body and gate regions of the device reduces the series resistance of the structure without incurring substantial optical power loss. That is, the use of increased dopant values in areas beyond the active region will allow for the series resistance to be reduced (and thus increase the modulating speed of the device) without incurring too large a penalty in signal loss. The dopant profiles within the gate and body regions are tailored to exhibit an intermediate value between the high dopant concentration in the contact areas and the low dopant concentration in the carrier integration window area.

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 method and apparatus comprising acquiring spectral measurements from an optical fiber sensor. The optical fiber sensor is an SBS-based sensor such as a BOTDA. The acquired measurements are of Brillouin interactions at a point along the optical fiber being excited by the lasers of the SBS-based sensor. The acquired measurements can comprise discreet measurements of the Brillouin gain spectrum (“BGS”) at the point along the fiber. The discreet measurements can be plotted as data points. A BGS can be defined by three parameters: the Brillouin frequency shift (“BFS”), the bandwidth and the peak gain. A Lorentzian curve can be used to model a BGS. A BFS can be determined by estimating the central frequency of the Lorentzian curve which is used to model the BGS.

Abstract: Provided is an electro-optic device. The electro-optic device includes an input Y-branch comprising a first input branch and a second input branch, an output Y-branch comprising a first output branch and a second output branch, a first optical modulator and a second optical modulator connected in series between the first input branch and the first output branch, and a third optical modulator connecting the second input branch to the second output branch. The first optical modulator comprises a PIN diode, and each of the second optical modulator and the third optical modulator comprises a PN diode.

Abstract: In a method and system to fabricate a compact optical device, a periodic group-delay device (PGDD) includes N optical input ports, N being a positive integer number, each port being configured to include one or more wavelength-division-multiplexing (WDM) channels; N corresponding optical output ports, each port being configured to include one or more WDM channels. The PGDD also includes a first slab waveguide region (FSWR) coupled to the N optical input ports, a second slab waveguide region (SSWR) coupled to the said N optical output ports, a first optical grating coupled to the FSWR, a second optical grating coupled to the SSWR, and; a third slab waveguide region (TSWR) coupled to at least one of the first and second optical gratings. The TSWR is configured to provide a configurable amount of dispersion to the N optical output ports. Optical signals carried by each WDM channel are processed concurrently and independently.

Abstract: An optical device includes a ridge-like optical waveguide portion, a mesa protector portion that is arranged in parallel to the optical waveguide portion, a resin portion that covers upper parts of the mesa protector portion and is disposed at both sides of the mesa protector portion, an electrode that is disposed on the optical waveguide portion, an electrode pad that is disposed on the resin portion located at an opposite side to the optical waveguide portion with respect to the mesa protector portion, and a connection portion that is disposed on the resin portion and electrically connects the electrode to the electrode pad.

Abstract: A planar lightwave circuit according to the present invention includes at least two interferometers each of which includes a plurality of optical waveguides, and dummy patterns that are provided on both sides of each of the optical waveguides of an interferometer, having an optical waveguide density lower than the highest optical waveguide density, of the interferometers. The optical waveguide density of an interferometer A1 is higher than the optical waveguide density of the interferometer A2. Therefore, the planar lightwave circuit includes dummy patterns provided on both sides of each optical waveguide of the interferometer A1.

Abstract: A first exemplary aspect of the present invention is a wavelength-tunable optical transmitter including: a semiconductor substrate (101); a wavelength-tunable light source that is formed on the semiconductor substrate (101) and includes at least a first reflector (102) of a wavelength-tunable type and a gain region (104); a semiconductor optical modulator formed on the semiconductor substrate (101); a first semiconductor optical waveguide (105c) that is formed on the semiconductor substrate (101) and smoothly connected to the wavelength-tunable light source; a second semiconductor optical waveguide (105d) that is formed on the semiconductor substrate and smoothly connected to the semiconductor optical modulator; a waveguide coupling region (108) in which the first and second semiconductor optical waveguides are collinearly coupled with a length LC that is not equal to m/2 (m: integer) times a complete coupling length LC0; and a second reflector (113) formed at an end of the waveguide coupling region (108).

Abstract: The waveguide-type polarizer includes: a Z-cut lithium niobate substrate; an optical waveguide having a ridge structure and formed on the substrate; a low refractive index film formed with a thickness satisfying 0?n·t/??0.3742 (where n is a refractive index, t (?m) is the thickness of the film, and ? (?m) is the wavelength of a light wave) on the side of the ridge structure; and a high refractive index film formed with a thickness satisfying 0.089?n·/? on the low refractive index film. The width of the ridge structure is a ridge width where the distribution of ordinary light of the light waves propagated through the optical waveguide changes and the distribution of extraordinary light of the light waves does not change, the angle of the ridge structure is less than 90°, and the waveguide-type polarizer has a function of transmitting extraordinary light.

Abstract: An optical hybrid circuit includes a multimode interference coupler; a first 2:2 optical coupler; a second 2:2 optical coupler; a third 2:2 optical coupler; and a phase controlling region. The first 2:2 optical coupler, the second 2:2 optical coupler, and the third 2:2 optical coupler are coupled to one of the pair of first output channels, the pair of second output channels, the pair of third output channels, and the pair of fourth output channels of the multimode interference coupler. The phase controlling region is provided in one or both of each pair of at least two pairs of output channels from among three pairs of output channels to which the first 2:2 optical coupler, the second 2:2 optical coupler, and the third 2:2 optical coupler are coupled, respectively.

Abstract: The present invention provides a wavelength interleaver comprising a first interleaving unit, a second interleaving unit and an adapting waveguide coupled between the first interleaving unit and the second interleaving unit; both the first interleaving unit and the second interleaving unit including an input waveguide, an output waveguide and a filter coupled between the input waveguide and the output waveguide. The present invention sets up the gap between the input waveguide and the filter, and the filter and the output waveguide for extending components usage specification of the signal transmission system. Therefore, there is no need to add unnecessary components in design, the size is smaller and the cost of the signal transmission system is reduced.

Abstract: An optical waveguide is described. This optical waveguide may be defined in a semiconductor layer, and may include a vertical slot that includes an electro-optic material having an electric-field-dependent index of refraction, and the electro-optic material may be other than a semiconductor in the semiconductor layer. Alternatively, the optical waveguide may include a vertical stack with two semiconductor layers that surround and partially overlap an intermediate layer, which includes the electro-optic material.

Abstract: The invention describes a modulator for the quadrature modulation of an optical carrier signal with an I- and a Q-portion, where a first optical multimode interferometer (MMI) splits the optical carrier signal into four branches and that in pairs of branches the I-portion and the Q-portion respectively is modulated with a Mach-Zehnder-Structure and a second optical multimode interferometer (MMI) combines the modulated I-portion and Q-portion again to one quadrature modulated optical output signal (OS).

Abstract: A method for optical chirp-free optical polarization modulation includes dividing a data modulated optical signal into a first optical path and a second optical path, using a Mach-Zehnder intensity modulator in the first optical path for imparting a ? phase difference between adjacent symbols of the data modulated optical signal in the first optical path, adjusting a delay and amplitude of symbols of the data modulated optical signal in the second path so that the symbols in the first path and the symbols in the second path are synchronized and have substantially equal power levels, and combining the first and second optical paths so that symbols from the first and second optical paths are in orthogonal polarizations.