Abstract: An apparatus comprising a substrate; a waveguide above the substrate; and an undercut into the substrate, the undercut beneath at least a portion of the waveguide, wherein a magnitude of a maximum length of the undercut is lower than a magnitude of a maximum depth of the undercut.

Abstract: Embodiments described herein may be related to apparatuses, processes, and techniques related to fully integrated optical coherent modulators on a silicon chip. These coherent modulators may be used to enable transmitters, receivers, transceivers, tunable lasers and other optical or electro-optical devices to be integrated on a silicon chip. In embodiments, the optical coherent modulators may be based on differential microring modulators that may be nested in a Mach-Zehnder Interferometer (MZI) configuration. Embodiments may also be directed to a miniaturized and fully integrated coherent modulators, which can enable terabit per second (Tbps) transceivers in a small form factor based on coherent modulation on a silicon chip. Other embodiments may be described and/or claimed.

Abstract: Reconfigurable non-reciprocal integrated-optics-based devices are disclosed. The non-reciprocal devices include: a phase-sensitive device, such as a microring waveguide; a magneto-optic layer; and an electromagnet. These elements are operatively coupled such that a magnetic field generated by current flow through the electromagnet gives rise to a non-reciprocal phase shift in the phase-sensitive device. The non-reciprocal phase shift leads to a difference in the way that a light signal travels in the forward and backward directions through one or more bus waveguides that are operatively coupled with the phase-sensitive element. The non-reciprocity is reversible by reversing the direction of drive current flow in the electromagnet, which enables the inter-port connectivity of the ports of these bus waveguides to be reconfigured based on the direction of the drive current flow. Examples of reconfigurable isolator and circulator embodiments are described.

Abstract: The present disclosure is directed to photonic wavelength division multiplexing (WDM) receivers with polarization diversity and/or low reflectance. In embodiments, a WDM receiver is provided with a splitter, a plurality of waveguides and a plurality of photodetectors in series. The waveguides having particular equal path lengths relationship from the splitter to respective ones of the photodetectors. In other embodiments, the WDM receiver is provided with a splitter, a looped waveguide, a plurality of photodetectors, and a plurality of variable optical attenuators (VOAs). The VOAs are configured to suppress reflection of signal beams back to the transmitter. In various embodiments, the WDM receiver is a receiver sub-assembly of a silicon photonic transceiver disposed in a silicon package. Other embodiments may be described and/or claimed.

Abstract: Embodiments described herein may be related to apparatuses, processes, and techniques related to coherent optical receivers, including coherent receivers with integrated all-silicon waveguide photodetectors and tunable local oscillators implemented within CMOS technology. Embodiments are also directed to tunable silicon hybrid lasers with integrated temperature sensors to control wavelength. Embodiments are also directed to post-process phase correction of optical hybrid and nested I/Q modulators. Embodiments are also directed to demultiplexing photodetectors based on multiple microrings. In embodiments, all components may be implements on a silicon substrate. Other embodiments may be described and/or claimed.

Abstract: Embodiments of the present disclosure are directed to multi-wavelength laser generator may produce light with a frequency comb having equally spaced frequency lines. In various embodiments, the laser generator includes first, a semiconductor gain element is used to provide gain to the laser being generated. Second, a ring resonator filter, or ring filter, is used to select the wavelength comb spacing. Third, a narrow-band DBR or narrow-band mirror is used to select the number of wavelengths that lase. Fourth, a wide-band or narrow-band mirror is used to provide optical feedback and to form the optical cavity. Fifth, a phase tuner section is used to align the cavity modes with the ring resonances (i.e. the ring filter modes) in order to reduce or minimize the modal loss. Other embodiments may be described and/or claimed.

Abstract: Reconfigurable non-reciprocal integrated-optics-based devices are disclosed. The non-reciprocal devices include: a phase-sensitive device, such as a microring waveguide; a magneto-optic layer; and an electromagnet. These elements are operatively coupled such that a magnetic field generated by current flow through the electromagnet gives rise to a non-reciprocal phase shift in the phase-sensitive device. The non-reciprocal phase shift leads to a difference in the way that a light signal travels in the forward and backward directions through one or more bus waveguides that are operatively coupled with the phase-sensitive element. The non-reciprocity is reversible by reversing the direction of drive current flow in the electromagnet, which enables the inter-port connectivity of the ports of these bus waveguides to be reconfigured based on the direction of the drive current flow. Examples of reconfigurable isolator and circulator embodiments are described.