Abstract: An electrical-optical modulator may include a first section configured for a first electrical-optical interaction between one or more optical waveguides and one or more signal electrodes. The electrical-optical modulator may include a second section configured to increase or decrease a relative velocity of signals of the one or more signal electrodes to optical signals of the one or more optical waveguides relative to the first section. The electrical-optical modulator may include a third section configured for a second electrical-optical interaction between the one or more optical waveguides and the one or more signal electrodes according to an opposite modulation polarity relative to the first section.

Abstract: An electrical-optical modulator may include one or more optical waveguides to propagate one or more optical signals in a direction of propagation. An optical waveguide of the one or more optical waveguides may include a time delay section, a first modulation section preceding the time delay section in the direction of propagation, and a second modulation section following the time delay section in the direction of propagation. The first modulation section and the second modulation section may be configured to be associated with opposite modulation polarities, and the time delay section may be configured to delay a phase of the one more optical signals relative to the first modulation section. The electrical-optical modulator may include one or more signal electrodes to propagate one or more signals in the direction of propagation in order to modulate the one or more optical signals through electrical-optical interaction.

Abstract: An on-chip wavelength locker may include an optical waveguide splitter to split an input optical signal received from a laser. The on-chip wavelength locker may include a plurality of integrated periodic optical elements, each to receive a respective portion of the input optical signal after splitting of the input optical signal by the optical waveguide splitter, and provide, based on the respective portion of the input optical signal, a respective periodic output optical signal of a plurality of periodic output optical signals. Each periodic output optical signal, of the plurality of periodic output optical signals, may be phase shifted with respect to other periodic output optical signals of the plurality of periodic output optical signals. The on-chip wavelength locker may include a plurality of integrated photodiodes to receive the plurality of periodic output optical signals in association with wavelength locking the laser.

Abstract: An electrical-optical modulator may include a first section configured for a first electrical-optical interaction between one or more optical waveguides and one or more signal electrodes. The electrical-optical modulator may include a second section configured to increase or decrease a relative velocity of signals of the one or more signal electrodes to optical signals of the one or more optical waveguides relative to the first section. The electrical-optical modulator may include a third section configured for a second electrical-optical interaction between the one or more optical waveguides and the one or more signal electrodes according to an opposite modulation polarity relative to the first section.

Abstract: An electrical-optical modulator may include a first section configured for a first electrical-optical interaction between one or more optical waveguides and one or more signal electrodes. The electrical-optical modulator may include a second section configured to increase or decrease a relative velocity of signals of the one or more signal electrodes to optical signals of the one or more optical waveguides relative to the first section. The electrical-optical modulator may include a third section configured for a second electrical-optical interaction between the one or more optical waveguides and the one or more signal electrodes according to an opposite modulation polarity relative to the first section.

Abstract: An electrical-optical modulator may include one or more optical waveguides to propagate one or more optical signals in a direction of propagation. An optical waveguide of the one or more optical waveguides may include a time delay section, a first modulation section preceding the time delay section in the direction of propagation, and a second modulation section following the time delay section in the direction of propagation. The first modulation section and the second modulation section may be configured to be associated with opposite modulation polarities, and the time delay section may be configured to delay a phase of the one more optical signals relative to the first modulation section. The electrical-optical modulator may include one or more signal electrodes to propagate one or more signals in the direction of propagation in order to modulate the one or more optical signals through electrical-optical interaction.

Abstract: An on-chip wavelength locker may include an optical waveguide splitter to split an input optical signal received from a laser. The on-chip wavelength locker may include a plurality of integrated periodic optical elements, each to receive a respective portion of the input optical signal after splitting of the input optical signal by the optical waveguide splitter, and provide, based on the respective portion of the input optical signal, a respective periodic output optical signal of a plurality of periodic output optical signals. Each periodic output optical signal, of the plurality of periodic output optical signals, may be phase shifted with respect to other periodic output optical signals of the plurality of periodic output optical signals. The on-chip wavelength locker may include a plurality of integrated photodiodes to receive the plurality of periodic output optical signals in association with wavelength locking the laser.

Abstract: A semiconductor waveguide optical device and a method of manufacturing of a semiconductor optical device are disclosed. The semiconductor waveguide optical device may include a gradient index waveguide for mode conversion and/or vertical translation of optical modes of step-index waveguides, which may be disposed on or over a same substrate as the gradient index waveguide. The gradient index waveguide may be epitaxially grown.

Abstract: A semiconductor waveguide optical device and a method of manufacturing of a semiconductor optical device are disclosed. The semiconductor waveguide optical device may include a gradient index waveguide for mode conversion and/or vertical translation of optical modes of step-index waveguides, which may be disposed on or over a same substrate as the gradient index waveguide. The gradient index waveguide may be epitaxially grown.

Abstract: A semiconductor waveguide optical device and a method of manufacturing of a semiconductor optical device are disclosed. The semiconductor waveguide optical device may include a gradient index waveguide for mode conversion and/or vertical translation of optical modes of step-index waveguides, which may be disposed on or over a same substrate as the gradient index waveguide. The gradient index waveguide may be epitaxially grown.

Abstract: A semiconductor waveguide optical device and a method of manufacturing of a semiconductor optical device are disclosed. The semiconductor waveguide optical device may include a gradient index waveguide for mode conversion and/or vertical translation of optical modes of step-index waveguides, which may be disposed on or over a same substrate as the gradient index waveguide. The gradient index waveguide may be epitaxially grown.

Abstract: An electro-optic waveguide polarization modulator (20) comprising a waveguide core (4) having first and second faces defining a waveguide core plane, a plurality of primary electrodes (22, 24) arranged at a first side of the waveguide core plane and out of said plane, and at least one secondary electrode (26) arranged at a second side of the waveguide core plane and out of said plane, wherein the electrodes (22, 24, 26) are adapted in use to provide an electric field having field components (13, 15) in two substantially perpendicular directions within the waveguide core (4) so as modulate the refractive index thereof such that electromagnetic radiation propagating through the core (4) is converted from a first polarization state to a second polarization state.

Abstract: An electro-optic waveguide polarisation modulator (20) comprising a waveguide core (4) having first and second faces defining a waveguide core plane, a plurality of primary electrodes (22, 24) arranged at a first side of the waveguide core plane and out of said plane, and at least one secondary electrode (26) arranged at a second side of the waveguide core plane and out of said plane, wherein the electrodes (22, 24, 26) are adapted in use to provide an electric field having field components (13, 15) in two substantially perpendicular directions within the waveguide core (4) so as modulate the refractive index thereof such that electromagnetic radiation propagating through the core (4) is converted from a first polarisation state to a second polarisation state.

Abstract: A horizontal access semiconductor photo detector (2) comprises a horizontal light absorbing layer (8) for converting light into photo-current which layer is configured to confine light within it in whispering gallery modes of propagation. The detector is configured to have a first waveguide portion (18) and a second light confining portion (20, 21) arranged such that the waveguide portion couples light into the detector and transfers light into the light confining portion so as to excite whispering gallery modes of propagation around the light confining portion. The light absorbing layer may be part of the light confining portion or alternatively light can be coupled into the light confining portion or alternatively light can be coupled into the light absorbing layer from the light confining portion by evanescent coupling. The excitation of whispering gallery modes within the light absorbing layer significantly increases the effective absorption coefficient of the light absorbing layer.

Abstract: A horizontal access semiconductor photo detector (2) comprises a horizontal light absorbing layer (8) for converting light into photo-current which layer is configured to confine light within it in whispering gallery modes of propagation. The detector is configured to have a first waveguide portion (18) and a second light confining portion (20, 21) arranged such that the waveguide portion couples light into the detector and transfers light into the light confining portion so as to excite whispering gallery modes of propagation around the light confining portion. The light absorbing layer may be part of the light confining portion or alternatively light can be coupled into the light confining portion or alternatively light can be coupled into the light absorbing layer from the light confining portion by evanescent coupling. The excitation of whispering gallery modes within the light absorbing layer significantly increases the effective absorption coefficient of the light absorbing layer.

Abstract: A device for spatially separating components of frequency in a primary radiation beam comprising means for separating the primary radiation beam into a plurality of secondary radiation beams, a plurality of electrically biasable waveguides forming a waveguide array, each for transmitting a secondary radiation beam to an output, wherein each waveguide has an associated optical delay line having a corresponding optical delay time, wherein each of the optical delay times is different. The device also comprises means for applying a variable electric field across each of the waveguides such that the phase of the secondary radiation beams transmitted through each may be varied by varying the electric field. The secondary radiation beams output from each of the waveguides interfere in a propagation region with a secondary radiation beam output from at least one of the other waveguides so as to form an interference pattern comprising one or more maximum at various positions in the propagation region.

Abstract: An optical mixing device (10) incorporates a rectangular multimode waveguide (14), with an input region (22) and an output region (24), two square section input waveguides (26, 28), and a detector (34). The input waveguides (26, 28) are arranged to provide first and second input radiation beams respectively to the input region (22), each beam being in the form of a square waveguide fundamental mode beam. Modal dispersion along the multimode waveguide (14) produces a single maximum incident on the detector (34) when the input beams are in phase with one another, and two maxima of like magnitude located on opposite sides of the detector (34) when the input beams are in antiphase. Intermediate these two situations three maxima are produced, the amplitudes depending on phase difference. The first and second input beams may be of like frequency producing a time-independent device output. The input beams may alternatively have different frequencies.

Abstract: A signal routing device (10) incorporates a multimode beamsplitter waveguide (20) connected by a set of parallel relay waveguides (22) to a multimode recombiner waveguide (24). Each relay waveguide (22) contains a respective electro-optic phase shifter (36). Sets of input and output waveguides (18, 28) are connected to the beamsplitter and recombiner waveguides (20, 24) respectively. The input and output waveguides (18, 28) are periodically spaced at off-center positions across the respective multimode waveguide transverse cross-section associated therewith. Radiation in any one of the input waveguides (18) is distributed between the relay waveguides (22) by virtue of modal dispersion in the beamsplitter waveguide (20). The phase shifters (36) apply a set of phase shifts to the distributed radiation. Modal dispersion in the recombiner waveguide (24) results in the phase shifted radiation providing a non-zero input to one or more of the output waveguides (28).

Abstract: An optical device (10) for use in beamsplitting, recombination and related applications incorporates a rectangular multimode waveguide (20) connecting a first coupling waveguide (18) to two second coupling waveguides (22, 24). The first coupling waveguide (18) operates in its fundamental mode and provides an input which excites a series of symmetric modes of the multimode waveguide (20). Modal dispersion along the multimode waveguide (20) provides for the input excitation (70a) to be transformed into separate output excitations (75a, 75b) cantered on respective second coupling waveguides (22, 24). The radiation intensity distribution (75) goes to zero at multimode waveguide end wall regions (54) between the second coupling waveguides (22, 24). This minimizes reflection and increased beamsplitting efficiency. The device (10) may be operated in reverse as a beam combiner.

Abstract: An electro-optic waveguide device (10) comprises an assembly of waveguides (30) connected to a common light input region (41) and forming a common far field diffraction pattern (44). The device (10) comprises an n.sup.+ GaAs substrate (14) bearing a waveguide lower cladding layer (16) of n.sup.+ Ga.sub.0.9 Al.sub.0.1 As, which is in turn surmounted by a waveguide core layer (18) of n.sup.- GaAs. The layer (18) has grooves (20) defining the waveguides (30), each of which has a respective Schottky contact (32). Each contact (32) is biased negative with respect to the substrate (14), which reverse biases the respective Schottky diode waveguide structure. The waveguide core layer (18) has electro-optic properties, and its refractive index varies with electric field. The phase of light emerging from each waveguide is therefore independently variable by means of its applied bias voltage.