The University of British Columbia

University of California

Washington State University

Huawei Technologies Canada Co., Ltd.

Sudip Shekhar

Lukas Chrostowski

Shahriar Mirabbasi

Hasitha Jayatilleka

Dinesh Bharadia

Zeqin Lu

Subhanshu Gupta

Erfan Ghaderi

Nicolas A F Jaeger

Md Nazmul Hasan

Ray Chung

Hossam A S Shoman

Mohammed Wadah Al Taha

Mohammed Ali Al-qadasi

Shyam Venkatasubramanian

Ahmad Sharkia

Samantha Grist

Ajith Sivadhasan Ramani

Karen C Cheung

Methods, circuits, and techniques for reflection cancellation. Laser output is tapped. A tapped portion of the laser output is phase shifted to generate a feedback signal, with the feedback signal being out-of-phase with a parasitic reflection of the laser output. The feedback signal is directed towards the laser such that the parasitic reflection and feedback signal are superpositioned before entering the laser. A magnitude and a phase of the feedback signal are such that superposition of the feedback signal and the parasitic reflection results in a resulting signal of lower magnitude than the parasitic reflection alone. During laser operation, a magnitude of the resulting signal is monitored and, as the parasitic reflection varies, the magnitude of the resulting signal is adjusted by adjusting at least one of the magnitude and the phase of the feedback signal in response to the monitoring of the resulting signal.

Method and circuit for reflection cancellation

An electromagnetic wave manipulation apparatus may include a substrate integrated with a liquid crystal. For example, the substrate may include one or more cavities filled with the liquid crystal. Alternatively and/or additionally, the substrate may include one or more layers of material interposed with the liquid crystal. The liquid crystal may be subjected to a voltage bias that alters the dielectric constant of the liquid crystal. Doing so may introduce a corresponding field offset between the input signal and the output signal of the apparatus. Subjecting the liquid crystal to different voltage biases may give rise to a spatial phase gradient that enables the apparatus to perform a variety of electromagnetic wave transformations such as reflection, refraction, retro-reflection, amplification, and cancellation. By performing such transformations, the apparatus may change the radiation pattern of its output signal, thus steering its output signal towards or away from a receiver.

Apparatus for electromagnetic wave manipulation

A 'frequency shifter' is a clock synthesis system, that includes either a multiplexer or a multi-modulus divider (MMD), a fractional frequency divider, a tunable delay element, a sawtooth signal generator, in addition to other synchronization and control circuits. The generated sawtooth signal is used to control the delay of the tunable delay element, which in turn is used to adjust the phase of the signal generated by either M-to-1 multiplexer or the MMD, reducing its timing errors, and improving the spectral purity of the generated clock signal.

Clock synthesis, distribution, and modulation techniques

A sensor architecture that uses fixed wavelength light and tunes a wavelength dependent response of a sensor may be used for detecting analytes in a wide range of applications. The sensor architecture is based on optical resonators or interferometers comprising optical waveguides. A resonance wavelength and/or transmission/reflection spectrum are affected by presence of an analyte adsorbed on a surface of the waveguide, and a setting of a phase modulator. The sensors include a sensor portion where part of the waveguide is exposed to a sample for sensing, and a phase modulator part. The phase modulator part may include a heater that is controlled to tune, or sweep, or modulate the resonant wavelength and/or spectrum of the sensor.

Photonic sensor using a fixed-wavelength laser

A discrete-time delay (TD) technique in a baseband receiver array is disclosed for canceling wide modulated bandwidth spatial interference and reducing the Analog-to-Digital Conversion (ADC) dynamic range requirements. In particular, the discrete-time delay (TD) technique first aligns the interference using non-uniform sampled phases followed by uniform cancellation using a cancellation matrix, such as, for example, a Truncated Hadamard Transform implemented with antipodal binary coefficients.

Spatial interference cancellation for simultaneous wireless and information power transfer

A method and apparatus for monitoring and feedback control of a photonic switch such as 2&#xd7;2 Mach-Zehnder Interferometer switch. Optical signals at an input and an output of the switch are monitored via optical taps. A sinusoidal time-varying phase shift is applied to one of the monitoring signals. An optical combiner then combines the monitoring signals. A photodetector monitors output of the optical combiner to provide a feedback signal. The amplitude of the feedback signal due to the time-varying phase shift increases with the amount of input signal present in the output signal. When the input signal is to be routed to the output (e.g. for a bar state), a controller manipulates the switch to maximize feedback signal amplitude. When the input signal is to be routed to a different output (e.g. for a cross state), the controller manipulates the switch to minimize feedback signal amplitude.

Method and apparatus for monitoring and controlling a photonic switch using phase sweeping

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Vancouver, Canada

Sudip Shekhar