Cisco Technology, Inc.

Shiyi Chen

Tao Ling

Mark Andrew Webster

Weizhuo Li

Prakash B Gothoskar

Ravi Sekhar Tummidi

Xunyuan Zhang

Embodiments herein describe a dual-layer Bragg grating that can be used as a dual-bandpass filter. In one embodiment, the dual-layer Bragg grating comprises at least two layers, each having an anti-symmetrical structure. In addition, the anti-symmetrical structures can have different pitches which are tuned to different bands. That is, the pitch of the anti-symmetrical structure in one layer can be set to reflect a first band in a received optical signal while the pitch of the anti-symmetrical structure in the other layer is set to reflect a second band in the received optical signal.

Double-layered antisymmetric two mode Bragg gratings

Embodiments include a fiber to photonic chip coupling system including a collimating lens which collimate a light transmitted from a light source and an optical grating including a plurality of grating sections. The system also includes an optical dispersion element which separates the collimated light from the collimating lens into a plurality of light beams and direct each of the plurality of light beams to a respective section of the plurality of grating sections. Each light beam in the plurality of light beams is diffracted from the optical dispersion element at a different wavelength a light beam of the plurality of light beams is directed to a respective section of the plurality of grating sections at a respective incidence angle based on the wavelength of the light beam of the plurality of light beams to provide optimum grating coupling.

Broadband optical coupling using dispersive elements

Embodiments herein describe a waveguide crossing that permits at least two optical signals to cross in two different directions. For example, one optical signal can propagate from left to right through the center of the waveguide crossing at the same time a second optical signal propagates up and down through the center of the crossing. In one embodiment, a circular disc is disposed at the center of the waveguide crossing through which the two (or more) optical signals pass. The shape of the circular disc can provide low insertion loss as the respective optical signals propagate between respective pairs of waveguides, as well as minimize cross talk between the two optical signals.

Single mode and multi-mode waveguide crossings

Embodiments presented in this disclosure generally relate to an optical device having a grating coupler for redirection of optical signals. One embodiment includes a grating coupler. The grating coupler generally includes a waveguide layer, a thickness of a waveguide layer portion of the waveguide layer being tapered, the thickness defining a direction, and a grating layer disposed above the waveguide layer and perpendicular to the direction where at least a grating layer portion of the grating layer overlaps the waveguide layer portion of the waveguide layer along the direction. Some embodiments are directed to grating coupler implemented with material layers above and a reflector layer below a grating layer, facilitating redirection and confinement of light that improves coupling loss and bandwidth. The material layers and reflector layer above and below the grating layer may be implemented with or without the waveguide layer being tapered.

Grating coupler

Aspects described herein include a mode multiplexer comprising a first optical waveguide extending between a first port and a second port. A first input mode of an optical signal entering the first port is propagated through the first optical waveguide to the second port. The mode multiplexer further comprises a second optical waveguide configured to evanescently couple with a coupling section of the first optical waveguide. A second input mode of the optical signal entering the first port is propagated through the second optical waveguide to a third port. The first optical waveguide further defines a filtering section between the coupling section and the second port, the filtering section configured to filter the second input mode.

Low-loss and low-crosstalk optical mode multiplexer and optical crossover

Embodiments herein describe a photonic platform where an AR coating is disposed between an optical grating and a semiconductor substrate. In one embodiment, the optical grating is disposed within an insulative layer. A first side of the insulative layer provides an optical interface where an external optical source can transmit an optical signal into, or a receive an optical signal from, the grating. A second, opposite side of the insulative layer contacts the AR coating. When the external optical source transmits light through the first side of the insulative layer, some of the light passes through the grating and reaches the AR coating. The AR coating prevents this light from being reflected back to the grating by the semiconductor layer which can cause interference that varies the coupling efficiency of the grating.

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Breinigsville, PA, United States of America

Shiyi Chen