Ciena Corporation

Bookham Technology Limited

Oclaro Technology Limited

Nortel Networks Corporation

Ian B Betty

Kim Bryon Roberts

Michael Y Frankel

Maurice M O'Sullivan

Michel Poulin

Robert Anthony Griffin

Christine Latrasse

Kelvin Prosyk

Alexandre Delisle-Simard

Michael Vitic

Vladimir S Grigoryan

Yuriy Greshishchev

Douglas McGhan

Christopher Watson

Maxime Poirier

Lloyd Nicholas Langley

Arash Khajooeizadeh

Jonathan Greenspan

Marcel Boudreau

Rick W Glew

An optical modulator includes multiple segments including modulator segments and a Radio Frequency (RF) crossing segment where RF lines extending a length of the modulator cross one another. The present disclosure includes optimization of one or more of a geometry of the RF crossing and a location of the RF crossing segment along the length. The geometry is selected so that the RF crossing segment appears as another segment having similar characteristics as modulator segments. The location of the RF crossing segment is selected to balance out fabrication error and phase efficiency.

Optical modulator robust to fabrication errors through an RF electrical crossing

Optical devices and systems including a polarization maintaining interconnect are disclosed. An optical assembly can include an optical component, a low-birefringence optical fiber and a polarization transformer. The polarization transformer is coupled between the optical component and the optical fiber. The polarization transformer is configured to transform between a substantially circularly-polarized light at the low-birefringence optical fiber and a substantially linearly-polarized light at the optical component.

Fiber optical package interconnect

In a ridge waveguide serial interferometer mode conversion is induced by a first mode conversion section, a phase difference between modes is introduced by propagation over a length of waveguide and optical interference is produced following further mode conversion induced in a second mode conversion section. The first mode conversion section has a first radius of curvature, which is equal to a second radius of curvature of the second mode conversion section. The ridge waveguide interferometer advantageously provides an equal phase dependency as a function of temperature.

Ridge waveguide serial interferometers

A coherent optical receiver Includes an electro-optic module coupled to an electronic signal processing Integrated circuit (IC) via a parallel analog transmission line bus. The electro-optic module receives and detects an optical channel light including a high-bandwidth signal modulated thereon. The electro-optic module includes: a single optical hybrid for mixing the optical channel light with a corresponding continuous wave local oscillator light to generate a mixed light containing the high-bandwidth data signal, at least one photodetector; and an analog frequency decimator for generating a set of parallel analog signals, each analog signal representing a respective portion of the high-bandwidth signal. The electronic signal processing IC includes a respective Analog-to-digital (A/D) converter for sampling each one of the set of parallel analog signals, and for generating corresponding parallel digital sample streams; and a digital signal processor (DSP) for processing the parallel digital sample streams to extract the high-bandwidth signal.

Parallel conversion between optical and digital

A Mach-Zehnder interferometer (MZI) incorporates a tunable multimode interference (MMI) coupler comprising a tunable MMI coupler with a tuning electrode on a surface of a tunable MMI region and an electrically insulating region provided within the tunable MMI region. The MMI region is tunable in response to detection of a photocurrent by a photodetector section. Such a tunable MZI is particularly advantageous in enabling a split ratio of an optical splitter, the split ratio and the splitter to be controlled in a particularly efficient manner.

Optical waveguide splitters

The present disclosure provides Radio Frequency (RF) drive level control systems and methods for an Electro-Optic (EO) M-ary Phase-Shift Keying (M-PSK) phase modulator. Specifically, an M-PSK drive waveform is tightly controlled for maximum symmetry in the associated constellation. In an exemplary embodiment, the present disclosure includes an M-PSK transmitter, an M-PSK electro-optic phase modulator, and phase modulation method that each control RF drive level based upon a carrier suppression ratio defined as a measure of ratio of a modulated time-averaged E-field to the magnitude of the E-field. In an exemplary embodiment, the carrier suppression ratio is measured based on a modulation depth measurement.

Radio frequency drive level control system and method for an electro-optic phase modulator

A method of testing a dual-polarization optical transmitter comprising a pair of polarization transmitters for respectively generating first and second polarization signals, and a polarization combiner for generating an optical signal composed of the first and second polarization signals with respective orthogonal polarization vectors. Each of the polarization transmitters is controlled to transmit respective polarization optical signals having predetermined characteristics. An output of the dual-polarization optical transmitter is tapped to obtain a first tap signal representative of the first polarization signal, and a second tap signal representative of the second polarization signal. A relative angle between respective polarization vectors of the tap signals is controlled, and the first and second tap signals combined to generate a combined light. A power level of the combined light is detected, and processed to obtain information about the performance of the dual polarization transmitter.

Self test of a dual polarization transmitter

A method for integrating optical devices in a single growth step by utilizing a combination of Selective Area Growth and Etch (SAGE) is provided. An first device is formed between a set of oxide-masked regions, whilst a second device is formed in an adjacent planar region. By use of Selected Area Growth and Etch (SAGE), in which the growth between the oxide-masked regions is greater than the growth in the planar region, and in which the etch rate in the area between the oxide-masked regions is substantially the same as that in the planar region, the number of active quantum layers for the first device are formed between the oxide-masked regions, and a different number of layers for the second device is formed in the planar region.

Method for integrating optical devices in a single epitaxial growth step

Through the introduction of an imaging multimode interference device in an integrated optical circuit, such performance degradations as lateral waveguide field oscillations and backreflections may be suppressed. The suppression of lateral waveguide field oscillations (that may occur due to misaligned optical coupling), in particular, can significantly reduce variations in the power splitting ratio of an optical power splitting structure, such as those employed by a Mach-Zehnder modulator.

Waveguide mode stripper for integrated optical components

A current tuned optical attenuator includes a Mach-Zehnder interferometer that relies on the creation of free carriers to create a phase difference in an optical signals along two waveguide arms.

Current tuned Mach-Zehnder optical attenuator

In order to provide a low power duobinary modulator for the long reach 10 Gb/s metro space that is relatively small and relatively inexpensive to make, a method of operating a Multiple Quantum Well (MQW) III-V Mach-Zehnder (MZ) optical modulator to have it provide a high-quality duobinary signal is provided. The method of operating the MQW III-V MZ optical modulator provided by the invention makes possible a high-quality duobinary modulator that has substantially balanced 'on' states. That is to say, both duobinary 'on' states are characterized by having respective output signals with substantially equivalent: peak intensities; high extinction ratios; and low frequency chirp.

Duobinary modulation scheme for a Mach-Zehnder optical modulator

An electro-optic modulator having a continuously adjustable chirp is provided. Optical signals input into the electro-optic modulator are divided into portions which are phase modulated in opposite senses, one portion imparted with a positive chirp and the other with a negative chirp. Variable couplers are used to adjust (by way of adjusting their coupling ratios) the amount of power allocated between the optical signals contributing to the positive chirp and the power of signals contributing to the negative chirp so that when the optical signals are combined an optical signal with an adjustable chirp is produced.

Growing community of inventors

Ottawa, Canada

Ian B Betty