Abstract: The invention relates to optical modulation devices and, in particular, monolithically integrated optical modulation devices. Disclosed herein is a monolithically integrated optical modulation device (200) that comprises: an input optical port (210); an output optical port (215); and an optical waveguide for guiding light from the input optical port to the output optical port. A portion of the optical waveguide is split into at least two branches. The waveguide is configured to cause a net 180° change in direction of the light while guiding said light from the input optical port to the output optical port such that the input optical port and the output optical port are positioned on a first edge of the device. At least some of the net 180° change in direction is achieved within the branches of the waveguide.

Abstract: There is disclosed a DBR laser and a method of use. The DBR laser comprises a phase section in a cavity of the DBR laser and configured to adjust an optical path length of the cavity. A DBR section comprises a frequency tuning system configured to adjust a Bragg frequency of the DBR section. A detector is configured to detect laser light transmitted through the DBR section.

Abstract: In accordance with one aspect of the present application there is provided a DBR, laser. The DBR laser comprises a phase section in a cavity of the DBR laser configured to adjust an optical path length of the cavity. The laser also comprises a DBR section comprising a frequency tuning system, the frequency tuning system comprising a resistance heater configured to apply heat to a grating of the DBR section in order to adjust a Bragg frequency of the DBR section. A detector is configured to detect laser light transmitted through the DBR section.

Abstract: There is disclosed a DBR laser and a method of use. The DBR laser comprises a phase section in a cavity of the DBR laser and configured to adjust an optical path length of the cavity. A DBR section comprises a frequency tuning system configured to adjust a Bragg frequency of the DBR section. A detector is configured to detect laser light transmitted through the DBR section.

Abstract: In accordance with one aspect of the present application there is provided a DBR, laser. The DBR laser comprises a phase section in a cavity of the DBR laser configured to adjust an optical path length of the cavity. The laser also comprises a DBR section comprising a frequency tuning system, the frequency tuning system comprising a resistance heater configured to apply heat to a grating of the DBR section in order to adjust a Bragg frequency of the DBR section. A detector is configured to detect laser light transmitted through the DBR section.

Abstract: The invention relates to optical modulation devices and, in particular, monolithically integrated optical modulation devices. Disclosed herein is a monolithically integrated optical modulation device (200) that comprises: an input optical port (210); an output optical port (215); and an optical waveguide for guiding light from the input optical port to the output optical port. A portion of the optical waveguide is split into at least two branches. The waveguide is configured to cause a net 180° change in direction of the light while guiding said light from the input optical port to the output optical port such that the input optical port and the output optical port are positioned on a first edge of the device. At least some of the net 180° change in direction is achieved within the branches of the waveguide.

Abstract: Methods and apparatus for use in coherent transmission and reception of optical data signals. An integrated optics block (100) for use in a coherent optical transmitter comprising: a beam splitter (102) configured to split an input light signal into first and second input light signals, to output the first input light signal for use in an optical transmitter chip and to output the second input light signal for use as a local oscillator signal; a polarization combiner (104) configured to combine first and second received modulated light signals to form an output; and a polarization rotator (106) configured to rotate the polarization of the second modulated light signal such that it is substantially orthogonal to the polarization of the first modulated light signal prior to combining.

Abstract: Methods and apparatus for use in coherent transmission and reception of optical data signals. An integrated optics block (100) for use in a coherent optical transmitter comprising: a beam splitter (102) configured to split an input light signal into first and second input light signals, to output the first input light signal for use in an optical transmitter chip and to output the second input light signal for use as a local oscillator signal; a polarisation combiner (104) configured to combine first and second received modulated light signals to form an output; and a polarisation rotator (106) configured to rotate the polarisation of the second modulated light signal such that it is substantially orthogonal to the polarisation of the first modulated light signal prior to combining.

Abstract: Sacrificial optical test structures are constructed upon a wafer of pre-cleaved optical chips for testing the optical functions of the pre-cleaved optical chips. The sacrificial optical structures are disabled upon the cleaving the optical chips from the wafer and the cleaved optical chips can be used for their desired end functions. The test structures may remain on the cleaved optical chips or they may be discarded.

Abstract: An assembly includes an etalon assembly for dynamically locking a frequency of an optical beam to a set frequency, the etalon assembly being external to a laser source assembly that outputs the optical beam. The etalon assembly includes an etalon that receives the optical beam and generates via interference effects a transmission beam, the etalon having a thermal tuning range greater than one half of a free spectral range of the etalon. The etalon assembly also includes an etalon heater mounted to the etalon such that the etalon heater is configured to adjust the temperature of the etalon. The assembly includes a controller configured to retrieve calibration data based on the set frequency, calculate a set temperature for the etalon using a thermal tuning algorithm and the calibration data, and control the etalon heater such that the etalon has a temperature equal to the calculated set temperature.

Abstract: An adjustable array includes a plurality of optical devices. Each adjustable array device has an optical light output therefrom and is configured whereby the corresponding optical lights of the plurality of optical devices have a predefined nonequivalent relationship relative to one another with respect to an output parameter. In response to a drive signal, the plurality of optical devices are further configured to adjust the corresponding optical lights with respect to the output parameter while substantially maintaining the predefined nonequivalent relationship.

Abstract: Sacrificial optical test structures are constructed upon a wafer of pre-cleaved optical chips for testing the optical functions of the pre-cleaved optical chips. The sacrificial optical structures are disabled upon the cleaving the optical chips from the wafer and the cleaved optical chips can be used for their desired end functions. The test structures may remain on the cleaved optical chips or they may be discarded.

Abstract: A widely tunable multi-mode semiconductor laser containing only two electrically active sections, being an optical gain section and a tunable distributed Bragg reflector section adapted to reflect at a plurality of wavelengths, wherein the gain section is bounded by the tunable distributed Bragg reflector section and a broadband facet reflector, and wherein the tunable distributed Bragg reflector section comprises a plurality of discrete segments capable of being selectively tuned, wherein the reflection spectra of one or more segments of the tunable distributed Bragg reflector section can be tuned lower in wavelength to reflect with the reflection spectrum of a further segment of the tunable distributed Bragg reflector section to provide a wavelength range of enhanced reflectivity. An optical transmitter comprising a light source that is such a widely tunable multi-mode semiconductor laser.

Abstract: Sacrificial optical test structures are constructed upon a wafer of pre-cleaved optical chips for testing the optical functions of the pre-cleaved optical chips. The sacrificial optical structures are disabled upon the cleaving the optical chips from the wafer and the cleaved optical chips can be used for their desired end functions. The test structures may remain on the cleaved optical chips or they may be discarded.

Abstract: An assembly includes an etalon assembly for dynamically locking a frequency of an optical beam to a set frequency, the etalon assembly being external to a laser source assembly that outputs the optical beam. The etalon assembly includes an etalon that receives the optical beam and generates via interference effects a transmission beam, the etalon having a thermal tuning range greater than one half of a free spectral range of the etalon. The etalon assembly also includes an etalon heater mounted to the etalon such that the etalon heater is configured to adjust the temperature of the etalon. The assembly includes a controller configured to retrieve calibration data based on the set frequency, calculate a set temperature for the etalon using a thermal tuning algorithm and the calibration data, and control the etalon heater such that the etalon has a temperature equal to the calculated set temperature.

Abstract: A widely tunable multi-mode semiconductor laser containing only two electrically active sections, being an optical gain section and a tunable distributed Bragg reflector section adapted to reflect at a plurality of wavelengths, wherein the gain section is bounded by the tunable distributed Bragg reflector section and a broadband facet reflector, and wherein the tunable distributed Bragg reflector section comprises a plurality of discrete segments capable of being selectively tuned, wherein the reflection spectra of one or more segments of the tunable distributed Bragg reflector section can be tuned lower in wavelength to reflect with the reflection spectrum of a further segment of the tunable distributed Bragg reflector section to provide a wavelength range of enhanced reflectivity. An optical transmitter comprising a light source that is such a widely tunable multi-mode semiconductor laser.

Abstract: A semiconductor laser diode comprises a semiconductor body having an n-region and a p-region laterally spaced apart within the semiconductor body. The laser diode is provided with an active region between the n-region and the p-region having a front end and a back end section, an n-metallization layer located adjacent the n-region and having a first injector for injecting current into the active region, and a p-metallization layer opposite to the n-metallization layer and adjacent the p-region and having a second injector for injecting current into the active region. The thickness and/or width of at least one metallization layer is chosen so as to control the current injection in a part of the active region near at least one end of the active region compared to the current injection in another part of the active region. The width of the at least one metallization layer is larger than a width of the active region.

Abstract: An adjustable array includes a plurality of optical devices. Each adjustable array device has an optical light output therefrom and is configured whereby the corresponding optical lights of the plurality of optical devices have a predefined nonequivalent relationship relative to one another with respect to an output parameter. In response to a drive signal, the plurality of optical devices are further configured to adjust the corresponding optical lights with respect to the output parameter while substantially maintaining the predefined nonequivalent relationship.

Abstract: There is described a laser assembly for providing light at a switchable output wavelength. The assembly comprises first and second tuneable lasers, each configurable to emit light at a laser wavelength chosen from a range of wavelengths. Light is transmitted from the first laser while the second laser is retuned to change the chosen laser wavelength thereof. Each laser comprises one or more thermally sensitive control components for controlling the operation of the laser and an additional component electrode located adjacent to at least one of the one or more control components. The laser is configured so that the sum of electrical currents supplied to each control component and its corresponding additional component remains substantially constant in use.

Abstract: A semiconductor laser diode comprises a semiconductor body having an n-region and a p-region laterally spaced apart within the semiconductor body. The laser diode is provided with an active region between the n-region and the p-region having a front end and a back end section, an n-metallisation layer located adjacent the n-region and having a first injector for injecting current into the active region, and a p-metallisation layer opposite to the n-metallisation layer and adjacent the p-region and having a second injector for injecting current into the active region. The thickness and/or width of at least one metallisation layer is chosen so as to control the current injection in a part of the active region near at least one end of the active region compared to the current injection in another part of the active region. The width of the at least one metallisation layer is larger than a width of the active region.