Google Inc.

Hong Liu

Ryohei Urata

Xiang Zhou

Cedric Fung Lam

Amin Vahdat

Xiaoxue Zhao

Bikash Koley

Christopher Lyle Johnson

Vijayanand Vusirikala

Zuowei Shen

Lieven Verslegers

Philip Michael Wells

Paul Germano

Erji Mao

Junlan Zhou

Dennis Charles Abts

Daoyi Wang

Michael Roger Marty

Melanie Beauchemin

Alexander Shraer

Ben Warren Segura

Pedram Zare Dashti

Peter Michael Klausler

Edward Crabbe

Vijay Vusirikala

Chris Johnson

Ilyas Mohammed

Jamyuen Ko

Teckgyu Kang

Xiangjun Zhao

Kevin Y Yasumura

Gurushankar Rajamani

Jill Berger

William F Edwards

Yut Loy Chan

Leon Poutievski

Woon Seong Kwon

Horia Alexandru Toma

Biao He

The disclosure provides for high bandwidth processing through the sharing of memory dies over a plurality of computing dies via an optical interchange. The optical interchange may be configured so as to operate as both an optical switch and optical demultiplexer. The optical switch configuration for the optical interchange allows for data to be written from any computing die to one of a plurality of memory dies via an optical connection. The optical demultiplexer configuration allows for data to be broadcast from a memory die to a plurality of the computing dies.

Systems for high-speed computing using an optical interchange

Coherent optical communications technology for recovery of 1D and 2D formatted optical signals. For example, 1D or 2D formatted signals that travel through fiber optic media may be recovered by separating the light into X- and Y-polarization components, rotating one polarization component (e.g., Y-component) into the polarization space of the other component (e.g., Y-component into the X-polarization space), delaying the rotated component enough to avoid destructive interference and combining the delayed component with the undelayed component to form a folded optical signal, which may then be processed as a X-polarized signal.

System, apparatus, and architecture for migrating an optical communication network

Polarization-folding coherent optical technology for short reach optical communication

A receiver system is provided for receiving a coherent Pulse Amplitude Modulation (PAM) encoded signal. The receiver system may include an optical polarization component configured to modulate a polarization of the received coherent PAM encoded signal. The receiver system may further include a digital signal processor (DSP) configured to perform polarization recovery between the received coherent PAM encoded signal and the LO signal using a first control loop, and to perform phase recovery between the received coherent PAM encoded signal and the LO signal using a second control loop.

Coherent receiver with mixed signal processing

The proposed technology allows for 1+1 optical protection and may improve coherent module output optical power by 3 dB over similar transmitter (Tx) and receiver (Rx) implementation complexity, as well as allow for integration into existing datacenter formats.

Dual-output coherent optical technology

Systems and methods are disclosed for two-dimensional optical transmission, including systems and methods for modulating and detecting two-dimensional short-reach optical communications. Two-dimensional optical transmissions may be generated by mapping a first data set to a first dimension of an optical signal and mapping a second data set to a second dimension of an optical signal. The encoded data for the first data set may be combined with the encoded data for the second data set so as to produce drive signals for a dual-drive modulator using a combination of both a common-mode and differential signal. The disclosed systems and methods also include dual-mode optical receivers that are configured to operate in either a one-dimensional or two-dimensional mode.

Two-dimensional optical modulation and detection technologies for optical communications

The technology generally relates to determining a status of an optical channel between two components. For example, the components may be connected via an optical link including a plurality of optical channels. A first portion of the optical channels may be in use such that a second portion of the optical channels may be redundant channels. The component may include a test generator that transmits and receives a data pattern over each channel. The test generator may determine, based on the received data pattern, a status of each of the channels. If the status of a given channel is a failure status, the component may divert data for the given channel to a redundant channel.

Reduce link repair rate with added redundancy in parallel optical links

The present disclosure provides for an example integrated optics assembly. The integrated optics assembly may include an optics mount, a substrate including a heat sink, and a photonic integrated circuit ('PIC'). The optics mount may be adapted to support a light source on a first end of the optics mount. The first end of the optics mount may be coupled to a region of the substrate including the heat sink. The heat sink may remove or dissipate the heat produced by the light source. A second end of the optics mount may be coupled to the PIC such that the optics mount extends between the substrate and the PIC. This may decrease the amount of space the optics mount takes up on the PIC thereby allowing the overall size of the PIC to be decreased. Decreasing the size of the PIC may allow for more PICS per wafer.

Laser light source co-packaged with photonic integrated circuit and substrate

A low-power coherent receiver is enabled with enhanced performance for intra-datacenter reach optical interconnection applications using several techniques. The first is a coherent skew adjustment technique which enables lower-power baud-rate ADC sampling and baud-rate-spaced coherent equalization. The second is a real-valued or mixed-valued low-power coherent equalization technique, where a single-tap real-valued 4&#xd7;4 MIMO equalizer plus four real-valued or two mixed-valued single-input single-out (SISO) equalizers are used for simultaneous polarization recovery, in-phase and quadrature (I/Q) phase error correction, and bandwidth equalization. The third is a power-efficient dual-DSP architecture to enhance coherent receiver performance, in which a complementary low-speed coherent DSP is introduced for optimal I/Q phase error correction and constellation decision parameters determination through more sophisticated algorithms that are too power hungry to be implemented in the primary high-speed DSP.

Low power coherent receiver for short-reach optical communication

A photonic integrated circulator can be fabricated by including a plurality of polarizing beam splitters and optical polarization rotators such that two copies of the optical signal are output at a receiver in substantially aligned polarization states. The circulator can be used for facilitating bi-directional communications between photonic integrated circuit devices, which are inherently polarization sensitive, while reducing signal loss.

Integrated optical circulator enabling polarization diversity

System for adjusting a reference constellation for demodulating an optical signal include a coherent electro-optical receiver configured to convert a received optical signal to a plurality of electrical signals, an array of analog-to-digital convertors configured to digitize the plurality of electrical signals, and processor logic. The processor logic is configured to process the digitized plurality of electrical signals using a reference constellation to yield a plurality of decoded signals and a signal quality measurement. The reference constellation includes an inphase component equal to an ideal inphase component plus an inphase offset and a quadrature component equal to an ideal quadrature component plus a quadrature offset. The processor logic is configured to determine an optimal inphase offset and optimal quadrature offset. The processor logic is configured to update the reference constellation using the optimal inphase offset and the optimal quadrature offset.

Mitigating optical modulator impairment for coherent optical communication systems

Growing community of inventors

Palo Alto, CA, United States of America

Hong Liu