616 results about "Electro-optic modulator" patented technology

The embodiment of the invention provides an electro-optical modulator and a light quantum computer. The electro-optical modulator comprises an electrode assembly and an optical waveguide assembly. The electrode assembly comprises a positive signal electrode, a negative signal electrode, a first grounding electrode and a second grounding electrode, and the positive signal electrode and the negative signal electrode are arranged between the first grounding electrode and the second grounding electrode. The optical waveguide assembly is configured to bear optical signals and comprises a first optical waveguide and a second optical waveguide, the first optical waveguide is located between the positive signal electrode and the negative signal electrode and used for bearing first optical signals, and the second optical waveguide is located between the first grounding electrode and the positive signal electrode or between the second grounding electrode and the negative signal electrode and used for bearing second optical signals. The carrier is used for bearing second optical signals. Constant-amplitude voltage signals with opposite phases are applied to the positive signal electrode and the negative signal electrode which are tightly coupled, so that the modulation efficiency can be improved, and the common-mode noise can be reduced.

The invention discloses an optical frequency comb generation method and device based on Brillouin scattering and an electro-optical modulator, and belongs to the field of photoelectric measurement. The method comprises the steps that a first laser and a second laser are used for generating pump light and seed light respectively, multi-wavelength pump light is generated through a cascade electro-optical modulator, the pump light and the seed light are emitted into a Sagnac loop, an optical frequency comb is output through the forward Brillouin scattering effect of an optical fiber and the electro-optical modulator, and the seed light and the pump light are output. The polarization controller is adjusted to optimize polarization state matching of the pump light and the seed light, so that the Brillouin scattering effect reaches the maximum value. The device is composed of a laser, an electro-optical modulator, a signal generator, an optical amplifier, an optical isolator, an optical coupler, a polarization controller and an optical fiber. The optical fiber forward Brillouin scattering effect and the electro-optical modulator are combined, the optical frequency comb giving consideration to the wide frequency spectrum and the narrow interval is generated, meanwhile, the comb tooth interval of the optical frequency comb can be accurately controlled by independently adjusting the frequency of the signal generator, and accurate measurement of signals or objects is achieved.

The invention provides a bent waveguide structure, an electro-optical modulator and a light quantum computer, and relates to the technical field of electro-optical modulation.The bent waveguide structure comprises an input waveguide, a bent waveguide and an output waveguide which are sequentially connected, and the bent waveguide comprises a substrate transmission waveguide layer, an input coupling part and an output coupling part; the input coupling part and the output coupling part are arranged at the two ends of the substrate transmission waveguide layer respectively, a shallow etching groove is formed between the input coupling part and the output coupling part, the input coupling part is connected with the input waveguide, and the output coupling part is connected with the output waveguide. Compared with the prior art, the shallow etching groove is formed between the input coupling part and the output coupling part, so that the thickness of the waveguide film at the bending part is reduced to ensure that the substrate transmission waveguide layer is of a single-mode structure, the transmission loss is reduced, and the bending waveguide is relatively independent from the input waveguide and the output waveguide, so that the transmission efficiency is improved. Therefore, the process precision of the bent waveguide can be independently adjusted, the process time is reduced, and the efficiency is improved.

Exemplary embodiments provide a device [e.g. a circuit, such as a control circuit] for generating a [e.g. time-variable] bias voltage VDC for an electro-optic modulator, wherein the device is configured to obtain an output power signal (I) dependent on an optical output power of the electro-optic modulator, wherein the device is designed to generate the bias voltage VDC on the basis of an amplitude ratio between the fundamental and the first harmonic of the output power signal (I) and on the basis of a phase angle of a pilot signal applied to the electro-optic modulator.

The invention relates to an electro-optical modulator, a preparation method thereof and an electro-optical chip. The electro-optical modulator comprises a substrate, an optical beam splitter, a first optical waveguide, a second optical waveguide, traveling wave electrodes and an electro-optical film, the traveling wave electrodes comprise a first signal electrode and a second signal electrode, the first signal electrode and the second signal electrode are sequentially arranged in the second direction, the first signal electrode and the second signal electrode form a differential electrode, and the first signal electrode and the second signal electrode are sequentially arranged in the second direction. The first signal electrode generates a first electric field when transmitting a first electric signal, the second signal electrode generates a second electric field when transmitting a second electric signal, the directions of the first electric field and the second electric field are opposite, and the refractive index of the electro-optical film is changed under the action of the electric fields to realize electro-optical modulation; part of the electro-optical film, the first optical waveguide overlaps with the first electric field, and the other part of the electro-optical film overlaps with the second electric field. According to the invention, the differential driving of the electro-optical modulator is realized based on the electro-optical film, and the anti-interference capability and the transmission distance of the electro-optical modulator are effectively improved.

The invention discloses a rotor and stator axial clearance online measuring device and method based on optical carrier microwave interference. The measuring device comprises a broadband light source, a first polarization maintaining optical fiber, an electro-optical modulator, a second polarization maintaining optical fiber, an optical fiber circulator, a first single-mode optical fiber and a coated optical fiber probe which are connected in sequence, and the coated optical fiber probe directly faces the axial end face to be measured; a first port of the optical fiber circulator is connected with the second polarization maintaining optical fiber, a second port of the optical fiber circulator is connected with the first single-mode optical fiber, and a third port of the optical fiber circulator is sequentially connected with the second single-mode optical fiber, the photoelectric detector, the signal conditioning unit, the signal acquisition unit and the digital processing unit; the signal acquisition unit is connected with the micro-control unit, the micro-control unit is connected with the microwave frequency sweep signal generation unit, and the microwave frequency sweep signal generation unit is connected with the electro-optical modulator. According to the invention, non-contact on-line high-precision measurement of the axial clearance of the rotor and the stator of the aero-engine under the conditions of limited measurement space and complex signal leading-out path can be realized.

The invention provides a lead zirconate titanate composite film with a high electro-optical coefficient, a preparation method of the lead zirconate titanate composite film and an electro-optical modulator, the lead zirconate titanate composite film comprises an insulating substrate, a buffer layer and a ferroelectric main body layer which are sequentially stacked, and the buffer layer is a lanthanum-doped lead zirconate titanate film; the ferroelectric main body layer is a lead zirconate titanate thin film and has (001) / (100) orientation. The composite film has a relatively high electro-optical coefficient, relatively low driving voltage and relatively high thermal stability.

An electro-optic modulator includes a light-splitting element, a light-combining element, two waveguide arms, and a modulation electrode. The two waveguide arms are connected between the light-splitting element and the light-combining element, and each waveguide arm includes a first single-mode waveguide portion, a first coupling portion, a multi-mode waveguide portion, a second coupling portion, and a second single-mode waveguide portion, wherein the width of either of the first single-mode waveguide portion and the second single-mode waveguide portion is smaller than the width of the multi-mode waveguide portion; the first coupling portion is configured to enable light to be coupled into the multi-mode waveguide portion from the first single-mode waveguide portion, and the second coupling portion is configured to enable light to be coupled into the second single-mode waveguide portion from the multi-mode waveguide portion; and the modulation electrode is configured to apply a modulation voltage to the multi-mode waveguide portion of the two waveguide arms.

The invention belongs to the technical field of optoelectronic devices, and provides a laser gyroscope frequency stabilization system and a frequency stabilization method thereof.The laser gyroscope frequency stabilization system comprises a large laser gyroscope to be subjected to frequency stabilization, an electro-optical modulator, an adjusting light path, a signal generator, a mode matching mirror set, a PID regulator, a frequency mixer, a photoelectric detector, an ultra-stable cavity, a low-pass filter, a computer and a data acquisition card; and a square transmission light path is arranged in the ultra-stable cavity. According to the invention, the problem of insufficient isolation caused by an optical isolator consisting of a polarization splitting prism and a 1 / 4 wave plate is effectively avoided, the influence of an optical feedback effect is reduced, and the optical isolator is better adapted to the field of high-precision measurement related to a large laser gyroscope.

A method for processing a radar signal based on a photonic fractional Fourier transformer comprises: transmitting a linear frequency modulation signal to targets to be detected, receiving echo signals of the targets to be measured, and loading the linear frequency modulation signal and the echo signals onto a single-frequency optical wave by an electro-optical modulator (S1); respectively biasing a sub-modulator and a parent modulator of the electro-optical modulator at different bias points, modulating the single-frequency optical wave by the electro-optical modulator based on the linear frequency modulation signal and the echo signals, and outputting a modulated optical signal (S2); converting the modulated optical signal by a photoelectric detector to a photocurrent (S3); and performing Fourier transform on the photocurrent to obtain a fractional Fourier spectrum, and obtaining distance information of the targets to be measured according to peak positions of each pulse signal in the fractional Fourier spectrum (S4).

The invention provides a BOTDR (Brillouin optical time domain reflectometry) system fusing Stokes-anti-Stokes light and a demodulation method, and belongs to the technical field of Brillouin distributed optical fiber sensing. The narrow linewidth laser is used for generating continuous optical signals; the input end of the coupler is connected with the laser, and the output end is connected with the pulse light branch and the local oscillator light branch. The pulsed light branch comprises a semiconductor optical amplifier, a random scrambler, a first erbium-doped optical fiber amplifier and a circulator which are connected in sequence; the local oscillator light branch comprises an electro-optical modulator, and the electro-optical modulator regulates and controls sideband frequency through a microwave module; the second erbium-doped optical fiber amplifier is used for extracting the Stokes light and the anti-Stokes light; the single-mode coupler mixes the double-sideband local oscillator light with the anti-Stokes light and the Stokes light; and the electrical beat frequency signals are acquired, filtered and enveloped and demodulated through an acquisition card. The detection capability of the Brillouin scattering signal is enhanced, the system structure is simplified, and the hardware cost and the maintenance difficulty are reduced.

The invention discloses an optical fiber signal transmission system and method based on quantum noise encryption, and relates to the technical field of optical fiber communication, and the system comprises a composite modulation transmitting module, a dispersion compensation relay module, a coherent receiving module and a digital signal processor. The composite modulation transmitting module comprises an electro-optical modulator and a quantum noise randomization encoder; the dispersion compensation relay module comprises an adjustable dispersion compensator and a Raman amplifier; the coherent receiving module comprises a local oscillator laser and a 90-degree optical mixer; a digital signal processor includes a clock recovery unit and a maximum likelihood sequence detector. All the modules are sequentially connected and cooperatively work. And the adjustable dispersion compensator dynamically applies reverse dispersion compensation calculated based on a dispersion coefficient and a transmission distance according to the dispersion amount monitored in real time. According to the invention, through technologies of quantum noise encryption, dynamic dispersion compensation, Raman amplification, coherent reception and the like, safe and efficient transmission with single-wave 400Gbps and 100km transmission bit error rate less than or equal to 1 * 10 <-12 > is realized.

According to the Y-type thin-film lithium niobate electro-optical modulator and the manufacturing method provided by the invention, the lithium niobate layer on the electro-optical modulator chip is etched into the corresponding bent waveguide structures, and the two bent waveguide structures are symmetrically arranged on the two sides of the Y-type waveguide structure, so that the height consistency of two optical paths is ensured; according to the bent waveguide structure, the length of the waveguide is guaranteed, meanwhile, the size of the space occupied by the waveguide is reduced, the waveguide with the same length can be carried by adopting a chip with smaller length, and meanwhile, the signal electrode and the ground electrode are arranged on the two sides of each section of straight waveguide in the bent waveguide structure, so that the size of the waveguide is reduced. The optical signal in the waveguide is modulated, and the modulation requirement of the electro-optical modulator is met.

Various embodiments may relate to an electro-optic modulator. The electro-optic modulator may include a waveguide configured to carry optical light along a longitudinal length of the waveguide. The electro-optic modulator may also include a first electrically conductive sub-wavelength grating on a first side of the waveguide, the first electrically conductive sub-wavelength grating including a plurality of fingers extending substantially perpendicular to the longitudinal length of the waveguide. The electro-optic modulator may further include a second electrically conductive sub-wavelength grating on a second side of the waveguide opposite the first side, the second electrically conductive sub-wavelength grating including a plurality of fingers extending substantially perpendicular to the longitudinal length of the waveguide. The electro-optic modulator may be configured to modulate the optical light upon application of a potential difference between the first electrically conductive sub-wavelength grating and the second electrically conductive sub-wavelength grating based on Pockels effect.

The present disclosure is directed, in general, to (1) nonlinear optical (NLO) chromophores containing spirofluorene-isophorone bridging groups, including (2) compositions / materials / resistive layers comprising NLO chromophores containing spirofluorene-isophorone bridging groups, and the methods of making the compositions / materials / resistive layers comprising NLO chromophores containing spirofluorene-isophorone bridging groups (e.g., methods of poling and / or drying, and the like), (3) uses of NLO chromophores containing spirofluorene-isophorone bridging groups in electro-optic devices (e.g., EOMs).

The invention provides an electro-optical modulator combining a slow light waveguide and a capacitive load type traveling wave. The electro-optical modulator comprises the slow light waveguide, a capacitive load type traveling wave electrode, a multi-mode interferometer, a mixed single-mode waveguide, a micro-ring structure and a micro-ring upper phase adjusting electrode. Capacitive load type traveling wave electrodes are arranged between and on the side edges of a pair of slow light waveguides which are arranged in parallel, the two ends of the slow light waveguides are connected to one end of a multimode interferometer through mixed single-mode waveguides respectively, the other end of the multimode interferometer is provided with two ports, one port is used for being connected with a micro-ring structure, and the other port is used for being connected with a micro-ring structure. The other port is used as the input end or the output end of the electro-optical modulator, and the two sides of the micro-ring structure are provided with micro-ring upper phase adjusting electrodes. The group refractive index and the working bandwidth of light can be regulated and controlled by adjusting the geometric parameters of the slow light waveguide, and low dispersion and high group refractive index can be realized in a wide optical bandwidth range; through a sectional capacitance load type slow wave electrode structure, the regulation and control of the microwave refractive index are realized, and the electro-optical modulation bandwidth is improved.

The invention provides an electro-optical modulator and a modulation method thereof, the electro-optical modulator comprises a substrate, a buried oxide layer and a lithium niobate waveguide layer are sequentially stacked on the substrate, and the lithium niobate waveguide layer comprises a first optical waveguide and a second optical waveguide; the electrode layer comprises a composite traveling wave electrode and a direct-current electrode, and the direct-current electrode is arranged on one side, in the signal transmission direction, of the composite traveling wave electrode; wherein the composite traveling wave electrode comprises a metal electrode and a polymer electrode, the metal electrode is embedded into the buried oxide layer, the polymer electrode is arranged on the surface of the buried oxide layer, and the composite traveling wave electrode is arranged between the first optical waveguide and the second optical waveguide and arranged on the side faces of the first optical waveguide and the second optical waveguide respectively; wherein the direct current electrode is arranged between the first optical waveguide and the second optical waveguide. The electro-optical modulator is high in electro-optical conversion efficiency, the plasma effect caused by light field coupling is effectively avoided, and the light loss of the device is remarkably reduced.

The invention belongs to the technical field of microwave photon links, and particularly relates to a high-resolution microwave photon frequency measurement system based on real-time Fourier transform. The link comprises a mode-locked laser, a first dispersion compensation module, a second dispersion compensation module, a dual-drive Mach-Zehnder modulator, a Mach-Zehnder modulator, a dispersion optical fiber, a time lens, an erbium-doped optical fiber amplifier, a photoelectric detector and an oscilloscope; the mode-locked laser outputs femtosecond Gaussian light pulses, and the femtosecond Gaussian light pulses are injected into the first dispersion compensation module and then stretched into chirp light pulses; modulating the chirp light pulse through electro-optical modulators which are connected in parallel; the modulated optical signal is subjected to time amplification processing through a dispersion optical fiber, a time lens, a second dispersion compensation module and an erbium-doped optical fiber amplifier in sequence; and the optical signal after time amplification processing is converted into a microwave pulse carrying frequency information of the signal to be detected by a photoelectric detector, and the microwave pulse is observed by an oscilloscope.

An integrated photonics millimeter wave (MMW) radar communication system based on analog phase modulation scheme includes an integrated photonics MMW radar communication signal transmitter, a radar receiver, and a communication receiver. The transmitter includes a radar communication signal analog phase modulation module, an optical frequency comb (OFC) module, an electro-optic modulator (EOM), an optical shaping filter, an optical power divider, a photoelectric detector, an electric power amplifier, and a transmitting antenna that are cascaded sequentially. The radar receiver includes a radar receiving antenna, an electric low-noise amplifier (LNA), an optical phase modulator, an optical bandpass filter (BPF), a low-speed photoelectric detector, an electric low-pass filter, and a low-speed oscilloscope that are cascaded sequentially. In the communication receiver, a communication receiving antenna is sequentially cascaded with an electric LNA, a frequency mixer, and an oscilloscope, and a voltage-controlled oscillator is cascaded with a frequency multiplier and then connected to the frequency mixer.

The invention relates to the technical field of optical fiber communication, in particular to a thin-film lithium niobate electro-optical modulator of a stepped electrode, which comprises a substrate, a buffer layer, an optical waveguide, a metal electrode and a transition layer, the optical waveguide is an X-shaped or Y-shaped cutting LN film, a traditional ridge-shaped structure is adopted, the optical waveguide is bonded to the thick SiO2 buffer layer on the substrate, the film can be prepared through various technologies such as ion implantation, wafer bonding and hot slicing, and in order to improve the electro-optical overlapping coefficient and reduce light absorption loss, a silicon dioxide transition layer is used for connecting the metal electrode and the optical waveguide. The metal electrode is of a stepped structure, the electrode can effectively reduce electrical loss and obtain high bandwidth, and the electrode is used for generating an electric field in the aspect of photoelectric efficiency; the electric field is used for changing the functional characteristics of the thin-film lithium niobate layer and further changing the optical transmission characteristics of the waveguide, so that electro-optical modulation is realized. Therefore, the problem that an existing electro-optical modulator is low in modulation efficiency is solved.

An electro-optical system having one or more electro-optical devices integrally formed within a substrate and associated methods are disclosed. An electro-optical system including an electro-optic switch is shown. An electro-optical system including an electro-optic modulator is shown. An electro-optical system including an optical resonator is shown.

The invention provides an electro-optical modulator based on a slow light effect. The electro-optical modulator comprises a substrate, a bottom electrode, an insulating layer, a slow light waveguide layer, an upper cladding and a signal electrode which are sequentially stacked from bottom to top. Wherein the slow light waveguide layer is a photonic crystal waveguide based on Z-cut film lithium niobate, the photonic crystal waveguide comprises a line defect waveguide and a plurality of air holes arranged in a triangular lattice structure, and the plurality of air holes are symmetrically arranged at two sides of the line defect waveguide. A photonic band gap is formed by a two-dimensional periodic optical medium structure formed by combining air holes arranged in a triangular lattice structure and Z-cut film lithium niobate, the slow light effect is achieved, and light waves in a specific frequency range can only be spread along a line defect waveguide by introducing the line defect waveguide. According to the invention, the interaction between the light field and the electric field is enhanced, the modulation efficiency and performance of the electro-optical modulator can be remarkably improved, and the development trend of miniaturization, integration and high speed of an existing communication network is met.

The invention relates to the technical field of laser, in particular to a high-signal-to-noise-ratio modulation transfer spectrum frequency stabilization light path system. The system comprises a laser, an optical isolator, a first half-wave plate, a first polarization splitting prism, an optical fiber coupler, a second half-wave plate, a second polarization splitting prism, a first reflecting mirror, an electro-optical modulator, a second reflecting mirror and a third polarization splitting prism, wherein the first half-wave plate is used for adjusting the power of frequency stabilization light; the second half-wave plate is used for adjusting the power ratio of pump light to probe light; a first quarter-wave plate, a second quarter-wave plate, an atomic gas chamber and a photoelectric detector; after the output of the laser is isolated by the optical isolator, the first half-wave plate and the first polarization splitting prism are matched to adjust the frequency stabilization total beam power to about 5mW; the pump light is modulated by the electro-optical modulator, the probe light and the pump light reversely interact in the atomic gas chamber in an anti-phase circular polarization state, and the signal-to-noise ratio of a modulation transfer signal and the stability of a frequency stabilization system are remarkably improved.

The application provides a Y-shaped thin film lithium niobate electro-optical modulator and a manufacturing method. A lithium niobate layer on an electro-optical modulator chip is etched into a corresponding curved waveguide structure, and two curved waveguide structures are symmetrically arranged on both sides of the Y-shaped waveguide structure, so that the heights of two light paths are consistent. The curved waveguide structure reduces the space size required by the waveguide while ensuring the waveguide length. For the waveguide with the same length, a chip with a smaller length can be used for mounting. The signal electrode and the ground electrode are arranged on both sides of each straight waveguide in the curved waveguide structure, the optical signal in the waveguide is modulated, and the modulation requirement of the electro-optical modulator is realized.

The invention discloses an OPGW optical cable lightning stroke positioning monitoring system and monitoring method based on distributed optical fiber sensing. Comprising a DFB laser, a first optical coupler, an acoustic optical modulator, a pulse signal generator, a scrambler, a first EDFA optical amplifier, a first optical isolator, an optical circulator, an FBG filter, an OPGW sensing optical cable, an electro-optical modulator, a microwave signal generator, a polarization regulator, a second EDFA optical amplifier, a second optical isolator, a second optical coupler and a variable optical attenuator which are connected in sequence. A third optical coupler, a balance detector, a low-frequency amplifier and a data processing module. The system can quickly and accurately position the lightning stroke position of the OPGW optical cable by measuring the Brillouin scattering frequency shift and the vibration state of the scattering signal.

The invention relates to a Mach-Zehnder electro-optical modulator, comprising first and second couplers, a first waveguide arm, a second waveguide arm, a third waveguide arm, a fourth waveguide arm, and first and second silicon nitride waveguides; the first silicon nitride waveguide and the second silicon nitride waveguide both comprise a first curved portion, a straight portion, and a second curved portion connected in sequence; the first coupler is respectively connected to one end of the first waveguide arm and one end of the second waveguide arm; the first silicon nitride waveguide is connected to the other end of the first waveguide arm through the first curved portion and to one end of the third waveguide arm through the second curved portion; the second silicon nitride waveguide is connected to the other end of the second waveguide arm through the first curved portion and to one end of the fourth waveguide arm through the second curved portion; the other end of the third waveguide arm is connected to the second coupler; the other end of the fourth waveguide arm is connected to the second coupler through a phase changer; the invention can reduce the active region capacitance of the modulator and improve the high frequency performance of the modulator.

The present invention relates to the fields of ferroelectric single crystal technology and acousto-optical device technology, particularly to a silicon-based lead magnesium niobate (PbMn) single crystal piezoelectric wafer structure, preparation method, and application. The structure comprises a silicon substrate on which a silicon dioxide layer and a single crystal piezoelectric thin film layer are sequentially disposed; the single crystal piezoelectric thin film layer is a PbMn-PT single crystal, including a binary PMN-PT single crystal thin film or a ternary PIN-PMN-PT single crystal thin film. This piezoelectric wafer structure on a silicon substrate can be used to fabricate various high-performance piezoelectric MEMS sensors, actuators, and electro-optical modulator devices. The resulting surface acoustic wave (SAW) filters and thin film bulk acoustic wave (BAW) filters exhibit a relative bandwidth increase of over 50%, and the resulting electro-optical modulators exhibit lower half-wave voltage and higher electro-optical modulation efficiency. The device volume can be reduced by 10 times, better meeting the future 6G communication requirements for higher efficiency, higher integration, and miniaturization of MEMS devices. This provides a novel multilayer piezoelectric wafer structure for the miniaturization and integration of piezoelectric MEMS and optoelectronic devices.

The invention provides an optical gain and electro-optical modulation integrated device and a preparation method thereof, and relates to the field of photoelectron, the optical gain and electro-optical modulation integrated device comprises a chip platform, and an electro-optical modulator and a gain waveguide which are integrated on the chip platform, and the chip platform is doped with rare earth ions in a region corresponding to the gain waveguide; the electro-optical modulator is used for modulating an input optical signal to obtain a modulated optical signal; and the gain waveguide is used for amplifying the modulated optical signal under the action of the pump light and the rare earth ions to obtain a target optical signal. The electro-optical modulator and the gain waveguide are integrated on the chip platform, cooperative work between the electro-optical modulator and the gain waveguide is achieved through rare earth ions, integrated design is achieved, the defects of discrete devices are overcome, and the design target of an on-chip photonic system can be met.

The invention relates to an electro-optical Mach-Zehnder modulator (1) comprising an input divider, first and second main waveguides (10p, 20p), and an output combiner (3). It also includes a first coplanar RF line (30) associated with the first main waveguide (10p). Finally, it includes a first additional waveguide (10a), not coupled to the input divider (2) and the output combiner (3), and having a positioning relative to a central track (33), a dimensioning and a doping profile symmetrical to those of the first main waveguide (10p), with respect to a plane of symmetry (Ps), orthogonal to the main plane (XY), parallel to the first main (10p) and additional (10a) waveguides, and passing through a center of the central track (33).

An electro-optic modulator including a waveguide and electrodes is described. The waveguide has a length proximate to at least a portion of the electrodes. Each electrode of the at least the portion of the electrodes is a traveling wave electrode and has an effective electro-optic modulation strength disposed along a length of the waveguide. The effective electro-optic modulation strength varies along the length of the waveguide.