Huawei Technologies Co., Limited

Huawei Technologies Canada Co., Ltd.

University of Toronto

University of Ottawa

Her Majesty the Queen in Right of Canada As Represented by the Minister of Industry Through the Communications Research Centre Canada

Patrick Dumais

Dominic John Goodwill

Eric Bernier

Mohammad Mehdi Mansouri Rad

Hamid Mehrvar

Dritan Celo

Chunshu Zhang

Yi Qian

Jia Jiang

Trevor Hall

Lukas Chrostowski

Wesley David Sacher

Claire Callender

Mehedi Hasan

Chantal Blanchetiere

Chris Ledderhof

Julian Noad

Glendon Lovell

Aspects of the disclosure provide a system and method used for time-of-flight lidar applications. Such systems and methods include a laser and pulse clipper which produces a shuttering effect to reduce the instantaneous output power from the pulse clipper. Accordingly the output from the pulse clipper is more suitable for time-of-flight lidar applications than that initially produced by the laser. This can allow for lasers which may otherwise exceed eye safety limits to be used for time-of-flight lidar applications without exceeding the eye safety limits.

Optical pulse clipper for lidar

An optical performance monitor comprises a first stage configured to receive a multiplexed optical signal. The first stage is tunable over a period. The first stage periodically filters the multiplexed optical signal over an optical channel to produce a fine filtered optical signal. A second stage is coupled to the first stage and has a second-stage transfer function. The second stage receives the fine filtered optical signal and produces one or a plurality of interfered optical signal pairs. A third stage is coupled to the second stage and has a third-stage transfer function. The third stage receives the optical signal pairs and demultiplexes the optical signal pairs to produce a plurality of demultiplexed optical signals. The combination of the second-stage transfer function and the third-stage transfer function is flatter over the optical channel than the third-stage transfer function.

Optical performance monitor

A LIDAR includes multiple light sources and a Liquid Crystal on Silicon (LCOS) device for controllably redirecting beams from each of the multiple light sources. The same or a different LCOS device can be used to controllably redirect reflected light to each of several corresponding light detectors. The LCOS device can be adjusted on a slower time scale while the light sources can be sequentially activated on a faster time scale. The LCOS device provides for fine steering control of LIDAR beams. The use of multiple light sources and detectors allows for a higher LIDAR scan rate.

Liquid crystal on silicon (LCOS) lidar scanner with multiple light sources

A coherent LIDAR method and apparatus are provided, in which two optical signals having a first frequency difference are reflected by an object. A difference in frequency between the corresponding received and reflected signals is determined. The frequency difference between the reflected signals differs from the first frequency difference due to Doppler effects. The object velocity is determined based on a comparison between the first frequency difference and the frequency difference in the reflected signals. The emitted signals can be produced by modulating a common light source. The reflected signals are inherently mixed at the receiver and further processed. Distance to the object can be determined by pulsing the emitted signals and measuring a time of flight by detecting corresponding pulse edges in the reflected signals, or by using phase sweeping. The emitter can be implemented using an optical phased array.

Coherent LIDAR method and apparatus

A photonic integrated circuit is provided that is adapted to compensate for an unintentional manufactured refractive index profile, such as a gradient, that arises due to manufacturing variance. The photonic integrated circuit including at least a thermal source and a spaced thermal sink to induce a thermal gradient in the photonic integrated circuit between the thermal source and the spaced thermal sink, the thermal gradient imparts an opposing thermal refractive index profile to correct for the manufactured refractive index profile. In some embodiments the photonic integrated circuit may be constructed with features that have an intentional structured refractive index profile that ensures any unintentional manufactured refractive index profile is correctable by the opposing thermal refractive index profile induced by the thermal source.

Apparatus and methods for accommodating manufacturing variance in optical photonic integrated circuits

The present invention provides a photonic device such as a variable optical attenuator, in which two signal components, propagating in modes of two different polarization states, are converted to two different modes of the same polarization state prior to modulation. The modulation of both components is performed by a single device which applies the same modulation strength to both components. The two signal components can be converted back to propagate in the two different polarization states following modulation.

Polarization independent photonic device having multimode component

A photonic platform includes a substrate, a buried oxide layer on the substrate, a first optical layer on the buried oxide layer, the first optical layer including one or more waveguides shaped as rib waveguides protruding upwardly from a common underlying slab and a second optical layer spaced above the first optical layer, the second optical layer defining an upper waveguide that crosses over the one or more partially etched waveguides. A low-loss photonic switch may be made using a silicon photonic platform implementing this waveguide crossing.

Waveguide crossing having rib waveguides

A LIDAR or other optical beamsteering apparatus includes an optical switch having a first port and a plurality of second ports. The switch is operated to establish an optical path between the first port and one of the second ports. The first port is connected to a light source or a light detector. Different second ports are connected to different surface/edge couplers. Each of the surface/edge couplers couples light from or to the apparatus in a different respective direction. The surface/edge couplers can be grating couplers. The direction of light coupling is configured due to the orientation of the surface/edge coupler and its grating period, where applicable. Surface/edge couplers can be arranged in a circular or concentric ring pattern. Grating couplers can be elongated.

Optical scanner with optically switched paths to multiple surface or edge couplers

An optical waveguide termination comprising a light-receiving inlet for receiving light to be terminated, a curved section extending from the inlet and having a continuously decreasing radius of curvature, and a light-terminating tip at an end of the curved section. The curved section may define a spiral waveguide, for example a logarithmic spiral, having a waveguide width that continuously decreases from the inlet to the tip.

Spiral optical waveguide termination

An optical waveguide termination includes a light-receiving inlet for receiving light to be terminated, a rib waveguide extending from the inlet, a doped, light-absorbing slab supporting the rib waveguide for absorbing light from the rib waveguide, and a tip at an end of the rib waveguide. The optical waveguide termination exhibits low back-reflection.

Optical waveguide termination having a doped, light-absorbing slab

A photonic platform based polarization controller providing a fixed target polarization is disclosed. The polarization controller has a polarization rotator splitter splitting the beam into first and second feeds corresponding to first and second orthogonal polarization components. A first Mach-Zehnder interferometer (MZI) stage provides a first phase delay between the first and second feeds based on a first control signal, and a first mixer mixes the first and second feeds to provide third and fourth feeds. A second MZI stage provides a second phase delay between the third and fourth feeds based on a second control signal, and a second mixer mixes the third and fourth feeds to provide fifth and sixth feeds. A third MZI stage provides a third phase delay between the fifth and sixth feeds based on a third control signal, and a third mixer mixes the fifth and sixth feeds to provide the fixed target polarization. An optical tap splits a portion of the beam.

Automatic endless polarization controller for a silicon-on-insulator platform

An optical attenuator and/or optical terminator is provided. The device includes an optical channel having two regions with different optical properties, such as an undoped silicon region which is less optically absorptive and a doped silicon region which is more optically absorptive. Other materials may also be used. A facet at the interface between the two regions is oriented at a non-perpendicular angle relative to a longitudinal axis of the channel. The angle can be configured to mitigate back reflection. Multiple facets may be included between different pairs of regions. The device may further include curved and/or tapers to further facilitate attenuation and/or optical termination.

Optical attenuator and fabrication method thereof

An optical coupling apparatus for coupling an optical fiber to a photonic chip is described. The apparatus includes a collimating microlens for collimating light from the optical fiber; a polarization splitting beam displacer for separating the light collimated by the collimating microlens into orthogonally polarized X and Y component beams; at least one focusing microlens for directing the X and Y component beams separately onto the photonic chip; and first and second surface grating couplers (SGCs) orthogonally disposed on the photonic chip and configured for operation in a same polarization state, for coupling the X and Y component beams, respectively, to the photonic chip.

Optical coupling using polarization beam displacer

A photonic integrated circuit (PIC) comprises an optical switch, a plurality of input edge couplers comprising a first input edge coupler and coupled to the optical switch, a plurality of input surface grating couplers (SGCs) comprising a first input SGC and coupled to the optical switch, a plurality of output edge couplers comprising a first output edge coupler and coupled to the optical switch, and a plurality of output SGCs comprising a first output SGC and coupled to the optical switch. A method of fabricating a PIC comprises patterning and etching a silicon substrate to produce a first optical switch, a first surface grating coupler (SGC) coupled to the first optical switch, and a first edge coupler coupled to the first optical switch.

Optical switches with surface grating couplers and edge couplers

A waveguide crossing includes a first waveguide and a second waveguide intersecting the first waveguide such that a gap equal to a width of the second waveguide is formed in the first waveguide, the second waveguide having a centerline defining a plane of symmetry. The first waveguide has a first waveguide section through which a single optical mode propagates, followed by a first non-adiabatic diverging taper, followed by a second waveguide section wider than the first waveguide section through which two even-order optical modes propagate, followed by a second non-adiabatic diverging taper, followed by a third waveguide section wider than the second waveguide section through which three even-order optical modes propagate. The three even-order modes synthesize to form a quasi-Gaussian beam that self-replicates symmetrically across the gap, thereby providing a low-loss waveguide crossing useful for photonic switching.

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Ottawa, Canada

Patrick Dumais