Bookham Technology Limited

Plessey Overseas Limited

Oclaro Technology Limited

Lumentum Technology UK Limited

Plessey Handel Und Investments A.g.

Ii-vi Laser Enterprise Gmbh

Oclaro Inc.

Oclaro Technology Limted

Andrew Cannon Carter

Neil David Whitbread

Andrew John Ward

Robert C Goodfellow

Lloyd Nicholas Langley

Adrian Perrin Janssen

Barrie Flintham

Douglas Charles John Reid

Douglas Reid

William James Stewart

Abram Jakubowicz

Norbert Lichtenstein

Stephen K Jones

Robert Graham Walker

David James Robbins

Boris Sverdlov

Colin Smith

Peter J Morgan

Samuel Davies

Michael Moser

Sam Davies

Michael Schwarz

Richard Davis

Steven James Borley

Giacinto Busico

Colin Edge

Frederick A Randle

Hans-Ulrich Pfeiffer

Stephen Gardner

Jörg Troger

David Williamson

Michael J Wale

Jens Buus

The invention relates to optical modulation devices and, in particular, monolithically integrated optical modulation devices. Disclosed herein is a monolithically integrated optical modulation device () that comprises: an input optical port (); an output optical port (); 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&#xb0; 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&#xb0; change in direction is achieved within the branches of the waveguide.

Optical modulation device

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. A controller is configured: to cause the phase section to apply a dither to the optical path length of the cavity or cause the frequency tuning system to apply a dither to the Bragg frequency of the DBR section; to use the detector to monitor intensity of light transmitted from the laser cavity via the DBR section during application of the dither; to determine a deviation from longitudinal mode centre operation on the basis of the monitored intensity; and to cause the frequency tuning system to adjust the Bragg frequency of the DBR section in order to reduce said deviation, or cause the phase section to adjust the optical path length of the cavity in order to reduce said deviation.

Active mode centre control

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. A controller is configured: to cause the phase section to apply a dither to the optical path length of the cavity or cause the frequency tuning system to apply a dither to the Bragg frequency of the DBR section; to use the detector to monitor intensity of light transmitted from the laser cavity via the DBR section during application of the dither; to determine a deviation from longitudinal mode centre operation on the basis of the monitored intensity; to cause the phase section to adjust the optical path length of the cavity in order to reduce said deviation; to determine an output frequency of the DBR laser on the basis of a resistance of the resistance heater; and to control the output frequency of the DBR laser by controlling power to the resistance heater.

Tuneable DBR laser without external frequency locker

Methods and apparatus for use in coherent transmission and reception of optical data signals. An integrated optics block () for use in a coherent optical transmitter comprising: a beam splitter () 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 () configured to combine first and second received modulated light signals to form an output; and a polarization rotator () 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.

Optical component

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.

Sacrificial waveguide test structures

A semiconductor distributed Bragg reflector laser configured for single longitudinal mode operation, having an optical waveguide comprising an optical gain section, a first reflector being a first distributed Bragg reflector (DBR) section comprising a grating configured to produce a reflection spectrum having one or more first reflective peaks, and a second reflector, wherein the first DBR section is configured to compensate for thermal chirp that is induced inhomogeneously along the length of the DBR section, in use.

Semiconductor DBR laser

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.

Thermal locker

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.

Array comprising a plurality of adjustable optical devices

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.

Tunable multi-mode laser

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. This arrangement results in substantially uniform current distribution near the front end of the active region. Advantageously, this uniform current density significantly improves the reliability of the laser diode.

Semiconductor laser diodes

The invention provides an optoelectronic device combining a vertical cavity surface emitting laser (VCSEL) and a photodetector for monitoring the output power of the vertical cavity surface emitting laser. To improve the signal-to-noise ratio of the photodetector, a light deflector is interposed between the photodetector and the VCSEL.

Optoelectronic device and method of operating optoelectronic device

A control () and a method of controlling a tunable laser having a gain section (), a phase change section () and a segmented Bragg grating reflector section () comprising a series of grating units (-) each of a different pitch, and an electrode (-) associated with each grating so that an electrical current is applicable to each individual grating. The control () includes a plurality of digitally controlled sources () of electrical current which are each connected to switch means (or) operable to independently connect each of said sources () to a respective electrode (e.g.or) associated with a grating (e.g.or) which is one of a subset of consecutive gratings (e.g.&) selected from said series of grating units (-).

Control for a tunable laser

A tuneable laser has a gain section bounded at one end by a first reflector in the form of a distributed Bragg reflector adapted to produce a comb of reflective peaks and on the other end by a second Bragg reflector, the second Bragg reflector adapted to reflect at a plurality of wavelengths and being capable of being varied selectively through discrete segments so that one or more segments of the Bragg reflector can be tuned to a lower wavelength to reflect with a segment reflecting at that lower wavelength to enhance the reflectivity at that lower wavelength.

Tuneable laser

A tuneable laser includes a gain section bounded at one end by a first reflector adapted to produce a comb of reflective peaks and on the other end by a second reflector in the form of a plurality of discrete grating units each capable of reflecting at one of the peaks of the comb, and each grating unit having at least two independently actuable electrodes, which when actuated independently one from the other is capable of reducing the reflectivity of the grating unit and in which at least two of the grating units have different pitches.

Growing community of inventors

Blisworth, United Kingdom

Andrew Cannon Carter