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.

According to one general aspect, an apparatus may include a memory circuit die configured to store a lookup table that converts first data to second data. The apparatus may also include a logic circuit die comprising combinatorial logic circuits configured to receive the second data. The apparatus may further include an optical via coupled between the memory circuit die and the logical circuit die and configured to transfer second data between the memory circuit die and the logic circuit die.

A system and method for using the system includes a first and second waveguide and optical receiver elements coupled therebetween. The optical receiver elements include a microring configured to admit light from and transfer light to at least one of the first and second waveguides, a photodetector, coupled to the microring, configured to detect light admitted to the microring, and an enable circuit, coupled to the microring, configured to be switched between a light admitting state to enable light to be admitted to the microring and a light rejection state to prevent light from being admitted to the microring. Each optical receiver element has a relative priority and are configured to asynchronously arbitrate among themselves for a token to place one of the enable circuits in the light admitting state to enable one of the optical receiver elements to receive and transmit data.

A system for integrated power combiners is disclosed and may include receiving optical signals in input optical waveguides and phase-modulating the signals to configure a phase offset between signals received at a first optical coupler, where the first optical coupler may generate output signals having substantially equal optical powers. Output signals of the first optical coupler may be phase-modulated to configure a phase offset between signals received at a second optical coupler, which may generate an output signal having an optical power of essentially zero and a second output signal having a maximized optical power. Optical signals received by the input optical waveguides may be generated utilizing a polarization-splitting grating coupler to enable polarization-insensitive combining of optical signals. Optical power may be monitored using optical detectors. The monitoring of optical power may be used to determine a desired phase offset between the signals received at the first optical coupler.

A silicon photonic integrated circuit with a heater. In some embodiments, the silicon photonic integrated circuit includes a first waveguide, on a top surface of the silicon integrated circuit, and a heater element, on the first waveguide. The heater element may include a first metal layer, on the first waveguide, and a second metal layer, on the first metal layer, the second metal layer having a different composition than the first metal layer, the second layer having a thickness of less than 300 nm.

A spot size converter includes: a first semiconductor waveguide structure having a first width enabling single mode propagation; a second semiconductor waveguide structure having a second width greater than the first width, a second semiconductor waveguide structure including an end face for optically coupling with an external waveguide; a third semiconductor waveguide structure having a third width greater than the first and second widths, the third semiconductor waveguide structure being optically coupled to the second semiconductor waveguide structure; and a single tapered waveguide having a first end portion connected to the third semiconductor waveguide structure, and a second end portion connected to the first semiconductor waveguide structure, the single tapered waveguide having a width gradually changing in a direction from the first end portion to the second end portion.

A waveguide configured for use with a near eye display (NED) device can include a light-transmissive substrate configured to propagate light rays through total internal reflection and a switchable diffractive optical element (DOE) on a surface of the substrate that is configured to input and/or output light rays to and/or from the substrate. According to some embodiments, the switchable DOE can include diffractive properties that vary across an area of the DOE. In some embodiments, the switchable DOE includes a surface relief diffraction grating (SRG) a surface of the substrate, a layer of liquid crystal material in contact with the SRG, a layer of conducting material in contact with the liquid crystal material configured to apply the voltage to the liquid crystal material, and a layer of insulating material over the layer of conducting material.

An electro-optic device 200 comprising a substrate in which first and second waveguides 202, 203 are formed. The device also comprises first and second electrodes 204, 205 comprising an optically transparent conductive material and including primary portions 204a, 205a overlying the first and second waveguides 202, 203 for electrically biasing the first and second waveguides. The device is configured such that one of the first and second electrodes includes one other portion 204b, 205b arranged alongside the primary portion 204a, 205a of the other of the first and second electrodes. This arrangement improves the electro-optic efficiency of the device without the need for a buffer layer in the electrodes.

Examples of diffractive devices comprise a cholesteric liquid crystal (CLC) layer comprising a plurality of chiral structures, wherein each chiral structure comprises a plurality of liquid crystal molecules that extend in a layer depth direction by at least a helical pitch and are successively rotated in a first rotation direction. Arrangements of the liquid crystal molecules of the chiral structures vary periodically in a lateral direction perpendicular to the layer depth direction to provide a diffraction grating. The diffractive devices can be configured to reflect light having a particular wavelength range and sense of circular polarization. The diffractive devices can be used in waveguides and imaging systems in augmented or virtual reality systems.

Examples of diffractive devices comprise a cholesteric liquid crystal (CLC) layer comprising a plurality of chiral structures, wherein each chiral structure comprises a plurality of liquid crystal molecules that extend in a layer depth direction by at least a helical pitch and are successively rotated in a first rotation direction. Arrangements of the liquid crystal molecules of the chiral structures vary periodically in a lateral direction perpendicular to the layer depth direction to provide a diffraction grating. The diffractive devices can be configured to reflect light having a particular wavelength range and sense of circular polarization. The diffractive devices can be used in waveguides and imaging systems in augmented or virtual reality systems.