Abstract: Devices to mitigate polarization mode dispersion are provided. An example device comprises: an input coupler configured to receive an optical signal comprising a first portion in a first polarization mode and a second portion in a second polarization mode, the second polarization mode about perpendicular to the first polarization mode; an output and/or an optical detector; and one or more optical components configured to convey the optical signal from the input coupler to the output and/or optical detector, one or more of the input coupler and the optical component(s) introducing a total differential group delay between the first and second portions. The optical component(s) comprising: a rotating component configured to rotate the first polarization mode of the first portion to the second polarization mode and rotate the second polarization mode of the second portion to the first polarization mode, to adjust the total differential group delay.

Abstract: The present disclosure describes a ventilator. The ventilator includes tubing configured to receive an input gas and a flow outlet airline in fluid communication with the tubing. The flow outlet airline includes an airline outlet, and the flow outlet airline is configured to supply an output gas to a user via the airline outlet. The ventilator includes an aerosol generator in fluid communication with the flow outlet airline. The aerosol generator is configured to receive an input liquid through an inlet tube and transform the liquid input into an aerosol. The ventilator further includes a breath detection airline including an airline inlet, wherein the airline inlet is separated from the airline outlet of the flow outlet airline, and configured to receive breathing gas from the user during exhalation by the user via the airline inlet. A method of supplying respiratory gas containing an aerosol is disclosed.

Abstract: An optical ring resonator structure with a backside recess is provided at a device. The device includes: a substrate having a device-side and a backside opposite the device-side; an optical ring resonator located on the device-side of the substrate; a heater having a shape complementary to the optical ring resonator, the heater positioned to heat the optical ring resonator; and one or more metal traces that connect at least to the heater, the metal traces configured to provide power to the heater and extending outward from the heater. The device further includes a recess on the backside of the substrate, the recess centered on the optical ring resonator, and having a diameter larger than both respective outer diameters of the optical ring resonator and the heater, the recess further extending laterally into a region of the one or more metal traces.

Abstract: A device and method for tuning a ring resonator using self-heating stabilization is provided. A light source is controlled to produce an optical signal, input to an optical ring resonator, at a power where self-heating shifts a resonance wavelength of the optical ring resonator by at least 10 picometers, the self-heating comprising absorption in the optical ring resonator of optical power from a received optical signal. Prior to using the optical ring resonator at least one of modulate and filter the optical signal at the optical ring resonator, a heater of the optical ring resonator is controlled to an operating temperature at which the resonance wavelength of the optical ring resonator is greater than a respective wavelength of the optical signal.

Abstract: A device that includes an optical coupler with a waveguide and waveguide index matched materials at an edge of a substrate, and a method of forming the device, is provided herein. The device comprises: a substrate having an edge, and an opening formed therein adjacent the edge; a layer of insulator on the substrate, which forms a bridge across the opening at the edge; a waveguide on the layer of insulator, the waveguide comprising a constant-width region and a tapered region terminating at the edge in a region of the opening; a first layer of optical epoxy in the opening, the optical epoxy indexed matched to the layer of insulator; and, a second layer of the optical epoxy on the tapered region, such that the optical epoxy optically contains an optical signal leaking from the waveguide in the tapered region.

Abstract: A device and method for tuning a ring resonator using self-heating stabilization is provided. A light source is controlled to produce an optical signal, input to an optical ring resonator, at a power where self-heating shifts a resonance wavelength of the optical ring resonator by at least 10 picometers, the self-heating comprising absorption in the optical ring resonator of optical power from a received optical signal. Prior to using the optical ring resonator at least one of modulate and filter the optical signal at the optical ring resonator, a heater of the optical ring resonator is controlled to an operating temperature at which the resonance wavelength of the optical ring resonator is greater than a respective wavelength of the optical signal.

Abstract: An optical ring resonator structure with a backside recess is provided at a device. The device includes: a substrate having a device-side and a backside opposite the device-side; an optical ring resonator located on the device-side of the substrate; a heater having a shape complementary to the optical ring resonator, the heater positioned to heat the optical ring resonator; and one or more metal traces that connect at least to the heater, the metal traces configured to provide power to the heater and extending outward from the heater. The device further includes a recess on the backside of the substrate, the recess centered on the optical ring resonator, and having a diameter larger than both respective outer diameters of the optical ring resonator and the heater, the recess further extending laterally into a region of the one or more metal traces.

Abstract: A device that includes an optical coupler with a waveguide and waveguide index matched materials at an edge of a substrate, and a method of forming the device, is provided herein. The device comprises: a substrate having an edge, and an opening formed therein adjacent the edge; a layer of insulator on the substrate, which forms a bridge across the opening at the edge; a waveguide on the layer of insulator, the waveguide comprising a constant-width region and a tapered region terminating at the edge in a region of the opening; a first layer of optical epoxy in the opening, the optical epoxy indexed matched to the layer of insulator; and, a second layer of the optical epoxy on the tapered region, such that the optical epoxy optically contains an optical signal leaking from the waveguide in the tapered region.

Abstract: A device and method for tuning a ring resonator using self-heating stabilization is provided. A light source is controlled to produce an optical signal, input to an optical ring resonator, at a power where self-heating shifts a resonance wavelength of the optical ring resonator by at least 10 picometers, the self-heating comprising absorption in the optical ring resonator of optical power from a received optical signal. Prior to using the optical ring resonator at least one of modulate and filter the optical signal at the optical ring resonator, a heater of the optical ring resonator is controlled to an operating temperature at which the resonance wavelength of the optical ring resonator is greater than a respective wavelength of the optical signal.

Abstract: Embodiments of the present disclosure provide devices and methods involving the thermal stabilization of microring resonators, such as microring modulators. Power is measured via an on-chip photodetector integrated with a drop port of the microring resonator, providing a local measurement of average power. This average power is employed as a feedback measure to actively control a heater that is integrated with the microring resonator, in order to stabilize the resonant wavelength of the microring resonator in the presence of thermal fluctuations. Employing such a system, a microring modulator can maintain error-free performance under thermal fluctuations that would normally render it inoperable.

Abstract: A device that includes a multi-segment ring modulator is provided. In particular, the device comprises: an optical waveguide; an optical ring modulator optically coupled to the optical waveguide; a first voltage control device along a first segment of the optical ring modulator; a second voltage control device along a second segment of the optical ring modulator; a first driver device configured to control the first voltage control device to a first voltage and a second voltage; and, a second driver device configured to control the second voltage control device to a third voltage and a fourth voltage. In particular implementations, a ratio of a length of the first segment to a length of the second segment can be one or more of about 2:1 and greater than 1:1, and non-linear driver devices can be used.

Abstract: A device and method for tuning a ring resonator using self-heating stabilization is provided. A light source is controlled to produce an optical signal, input to an optical ring resonator, at a power where self-heating shifts a resonance wavelength of the optical ring resonator by at least 10 picometers, the self-heating comprising absorption in the optical ring resonator of optical power from a received optical signal. Prior to using the optical ring resonator at least one of modulate and filter the optical signal at the optical ring resonator, a heater of the optical ring resonator is controlled to an operating temperature at which the resonance wavelength of the optical ring resonator is greater than a respective wavelength of the optical signal.

Abstract: An adiabatic elliptical optical coupler device is provided comprising: a substrate having an edge; a first waveguide on the substrate, the first waveguide comprising a constant-width region and a tapered region terminating at the edge of the substrate, the tapered region having a smaller width at the edge than at the constant-width region; and, a pair of second waveguides on the substrate, and located on either side of the tapered region, each of the pair of the second waveguides terminating at the edge at a first end and extending to a second end adjacent the constant-width region, and distal the first end; at least a portion of each of the pair of second waveguides being tapered, and optically coupled to the first waveguide to transition a mode of an optical signal in the first waveguide from an elliptical mode at the edge towards a confined mode.

Abstract: A device that includes a multi-segment ring modulator is provided. In particular, the device comprises: an optical waveguide; an optical ring modulator optically coupled to the optical waveguide; a first voltage control device along a first segment of the optical ring modulator; a second voltage control device along a second segment of the optical ring modulator; a first driver device configured to control the first voltage control device to a first voltage and a second voltage; and, a second driver device configured to control the second voltage control device to a third voltage and a fourth voltage. In particular implementations, a ratio of a length of the first segment to a length of the second segment can be one or more of about 2:1 and greater than 1:1, and non-linear driver devices can be used.

Abstract: An adiabatic elliptical optical coupler device is provided comprising: a substrate having an edge; a first waveguide on the substrate, the first waveguide comprising a constant-width region and a tapered region terminating at the edge of the substrate, the tapered region having a smaller width at the edge than at the constant-width region; and, a pair of second waveguides on the substrate, and located on either side of the tapered region, each of the pair of the second waveguides terminating at the edge at a first end and extending to a second end adjacent the constant-width region, and distal the first end; at least a portion of each of the pair of second waveguides being tapered, and optically coupled to the first waveguide to transition a mode of an optical signal in the first waveguide from an elliptical mode at the edge towards a confined mode.

Abstract: An apparatus, system and method of resonance wavelength alignment for ring modulators is provided which includes: an optical input bus configured to convey a given optical input signal having a given optical frequency; an optical ring modulator configured to: receive and modulate the input signal from the input bus; an optical output bus configured to convey a modulated optical signal from the ring; a first optical tap on the input bus configured to sample the input signal; a second optical tap configured to sample the modulated signal; a controller in communication with the ring, the first tap and the second tap, the controller configured to: determine a current insertion loss of the ring from respective signals received from both the first tap and the second tap; and, control the ring in a feedback loop with the current insertion loss until the current insertion loss comprises a given insertion loss.

Abstract: An avalanche photodiode in a photonic integrated circuit with a waveguide optical sampling device is provided. Specifically, disclosed herein is a device which includes: an avalanche photodiode (APD) comprising a light input, an electrical output and a gain control input; a waveguide configured to convey on optical signal to the light input of the APD; an optical sampling device on the waveguide configured to sample an input light level of the optical signal, the waveguide and at least a portion of the optical sampling device formed from a photonic integrated circuit (PIC); and, a controller in communication with the optical sampling device and the gain control input, the controller configured to control a bias voltage to the gain control input of the APD based on the input light level of the optical signal received at the optical sampling device.

Abstract: A single laser multi-frequency transmitter is provided, comprising: a laser generating given modes; an optical input bus; a common optical output bus; coupling optics coupling the laser to the optical input bus; a plurality of ring resonator filters: arranged in series along the optical input bus in a one-to-one relationship with a sub-band of the given modes; optically coupled to both the optical input bus and the common optical output bus; and each configured to couple one respective frequency from the sub-band to the common optical output bus; and, a plurality of ring resonator modulators: arranged in series along the common optical output bus in a one-to-one relationship with the plurality of ring resonator filters; and each configured to modulate one given respective frequency from the sub-band so that all modes in the sub-band are modulated on the common optical output bus.

Abstract: Optical dispersion compensation devices are provided herein that are based on one or more optical ring resonators. The degree of dispersion compensation can be selected by controlling the degree of under-coupling and by tuning physical properties of the optical ring resonators. In a first implementation, an optical ring resonator under-coupled to an optical throughput bus can be used to provide positive or negative dispersion compensation depending on tuning of the optical ring resonator, which widens the dispersion window. In a second implementation, an over-coupled optical ring resonator can be added to the optical throughput bus to provide a cascaded filter. In a third implementation optical ring resonators arranged in series between an optical input bus and an optical output bus can be used to both tune dispersion compensation and provide demultiplexing.

Abstract: A single laser multi-frequency transmitter is provided, comprising: a laser generating given modes; an optical input bus; a common optical output bus; coupling optics coupling the laser to the optical input bus; a plurality of ring resonator filters: arranged in series along the optical input bus in a one-to-one relationship with a sub-band of the given modes; optically coupled to both the optical input bus and the common optical output bus; and each configured to couple one respective frequency from the sub-band to the common optical output bus; and, a plurality of ring resonator modulators: arranged in series along the common optical output bus in a one-to-one relationship with the plurality of ring resonator filters; and each configured to modulate one given respective frequency from the sub-band so that all modes in the sub-band are modulated on the common optical output bus.