Abstract: Embodiments include apparatuses, methods, and systems including a dynamic polarization controller (DPC) to receive a first light beam and a second light beam, to adjust a rotation of a state of polarization (SOP) of the first light beam and the second light beam to generate a third light beam and a fourth light beam, under the control of a first control signal, a second control signal, and a third control signal. The first control signal may be related to a phase difference between the third light beam and the fourth light beam, the second control signal may be related to an intensity difference between the third light beam and the fourth light beam, and the third control signal may be related to a rotation of a SOP of the third light beam and the fourth light beam. Other embodiments may also be described and claimed.

Abstract: Embodiments include apparatuses, methods, and systems including a semiconductor photonic device having a waveguide disposed above a substrate. The waveguide has a first section including amorphous silicon with a first refractive index, and a second section including crystalline silicon with a second refractive index different from the first refractive index. The semiconductor photonic device further includes a heat element at a vicinity of the first section of the waveguide. The heat element is arranged to generate heat to transform the amorphous silicon of the first section of the waveguide to partially or completely crystallized crystalline silicon with a third refractive index. The amorphous silicon in the first section may be formed with silicon lattice defects caused by an element implanted into the first section. Other embodiments may also be described and claimed.

Abstract: 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.

Abstract: Embodiments include apparatuses, methods, and systems including a dynamic polarization controller (DPC) to receive a first light beam and a second light beam, to adjust a rotation of a state of polarization (SOP) of the first light beam and the second light beam to generate a third light beam and a fourth light beam, under the control of a first control signal, a second control signal, and a third control signal. The first control signal may be related to a phase difference between the third light beam and the fourth light beam, the second control signal may be related to an intensity difference between the third light beam and the fourth light beam, and the third control signal may be related to a rotation of a SOP of the third light beam and the fourth light beam. Other embodiments may also be described and claimed.

Abstract: Embodiments include apparatuses, methods, and systems including a semiconductor photonic device having a waveguide disposed above a substrate. The waveguide has a first section including amorphous silicon with a first refractive index, and a second section including crystalline silicon with a second refractive index different from the first refractive index. The semiconductor photonic device further includes a heat element at a vicinity of the first section of the waveguide. The heat element is arranged to generate heat to transform the amorphous silicon of the first section of the waveguide to partially or completely crystallized crystalline silicon with a third refractive index. The amorphous silicon in the first section may be formed with silicon lattice defects caused by an element implanted into the first section. Other embodiments may also be described and claimed.

Abstract: A method and apparatus for monitoring and feedback control of a photonic switch such as 2×2 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.

Abstract: Embodiments include apparatuses, methods, and systems including a dynamic polarization controller (DPC) to receive a first light beam and a second light beam, to adjust a rotation of a state of polarization (SOP) of the first light beam and the second light beam to generate a third light beam and a fourth light beam, under the control of a first control signal, a second control signal, and a third control signal. The first control signal may be related to a phase difference between the third light beam and the fourth light beam, the second control signal may be related to an intensity difference between the third light beam and the fourth light beam, and the third control signal may be related to a rotation of a SOP of the third light beam and the fourth light beam. Other embodiments may also be described and claimed.

Abstract: A method and apparatus for monitoring and feedback control of a photonic switch such as 2×2 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.

Abstract: The disclosure demonstrates n-doped resistive heaters in silicon waveguides showing photoconductive effects with high responsivities on the order of 100 mA/W. These photoconductive heaters, integrated into microring resonator (MRR)-based filters, can be used to automatically tune and stabilize the filters' resonance wavelength to the input laser-wavelength. This is achieved without requiring dedicated defect implantations, additional material depositions, dedicated photodetectors, or optical power tap-outs. Series-coupled higher-order MRR-based filters can be automatically tuned by sequentially aligning the resonance of each MRR to the laser-wavelength by using photoconductive heaters to monitor the light intensity in each MRR. Embodiments allow for the automatic wavelength stabilization of MRR-based optical circuits.