University of California

Other

Lockhead Martin Corp.

The United States of America, As Represented by the Director, National Security Agency

Sung-Joo Ben Yoo

Fei Xue

Julie Taylor

David A B Miller

Robert Patti

Chad Elliott Ogden

Samuel Trent Thurman

Roberto Proietti

Pouya Fotouhi

Chuan Qin

Burcu Ercan

Neal Eugene Hurlburt

Hongbo Lu

Marjan Fariborz

Yu Zhang

Christopher A Mineo

Ke Wen

Kuanping Shang

One embodiment provides a computer system. The computer system includes a plurality of processing units, a plurality of memory channels, and an arrayed waveguide grating router (AWGR). A respective processing unit is coupled to an array of tunable optical transceivers. A respective memory channel is coupled to a plurality of memory banks. Each memory bank is associated with a unique optical wavelength and can be accessed via the corresponding wavelength. Each memory channel is coupled to an individual output port of the AWGR, and the tunable optical transceivers of each processing unit are respectively coupled to different input ports of the AWGR, thereby allowing each processing unit to communicate with any memory bank associated with any memory channel using an appropriate tunable optical transceiver tuned to the corresponding optical wavelength associated with the memory bank.

Ultrahigh-bandwidth low-latency reconfigurable memory interconnects by wavelength routing

During operation, the system receives an optical input signal, and also receives a reference optical frequency comb (OFC) signal. Next, the system uses a gapless spectral demultiplexer to spectrally slice the optical input signal to produce a set of spectral slices. The system also uses a high-contrast demultiplexer to strongly isolate each combline of the reference OFC signal to produce a set of reference comblines. Next, in a parallel manner, the system demodulates each spectral slice in the set of spectral slices centered on a single reference combline in the set of reference comblines to produce a set of baseband I/Q signals, wherein each spectral slice is demodulated based on a known code sequence. The system then digitizes the set of baseband I/Q signals to produce a set of digitized signals. Finally, the system processes the set of digitized signals to directly reconstruct a waveform for the optical input signal.

High-speed optical analog-to-digital converter based on compressive sensing

The disclosed system implements a bandwidth-reconfigurable optical interconnect, which couples optical signals between N interconnect inputs and N interconnect outputs. The system includes an arrayed waveguide grating router (AWGR), which provides cyclic, single-wavelength, all-to-all routing between N AWGR inputs and N AWGR outputs. The system also includes a wavelength-insensitive switch, which provides all-wavelength, all-to-all connectivity between N wavelength-insensitive inputs and N wavelength-insensitive outputs. The system additionally includes a wavelength-selective input switch, which selectively directs up to L wavelengths from each of the N interconnect inputs into a corresponding input of the wavelength-insensitive switch, wherein unselected wavelengths from each of the N interconnect inputs pass into a corresponding AWGR input. Finally, the system includes a wavelength-selective output switch, which selectively directs up to L wavelengths from each of the N wavelength-insensitive outputs into a corresponding interconnect output, wherein each of the N AWGR outputs pass into a corresponding interconnect output.

Bandwidth-reconfigurable optical interconnect based on wavelength and spatial switching

The disclosed embodiments relate to a system that implements a photonic neuron. This photonic neuron includes: an excitatory-input photo detector that converts an optical excitatory input signal into a corresponding electrical excitatory input signal; and an inhibitory-input photo detector that converts an optical inhibitory input signal into a corresponding electrical inhibitory input signal. It also includes an electrical neuron that receives the electrical excitatory and inhibitory input signals, and generates an electrical output signal, which includes periodic voltage spikes that are triggered by integration of the electrical excitatory and inhibitory input signals. Finally, the photonic neuron includes a light-emitting output device, which converts the electrical output signal into a corresponding optical output signal.

Implementing a neuromorphic computing system using nanophotonic neurons

An imaging spectro-polarimetry system includes a polarizer, a tunable laser, a number of optical nodes and an image processing circuit. The polarizer produces polarized light using light received from an object. The tunable laser generates optical local oscillator (LO) signals. Each optical node receives the polarized light and an optical LO signal, performs a heterodyne mixing and generates a digital signal. The image processing circuit receives digital signals from the optical nodes and generates a magnetogram of the object. The polarizer, the tunable laser, the plurality of optical nodes and the image processing circuit are implemented on a photonic integrated circuit (PIC), and the polarized light includes right and left circularly polarized light.

Imaging spectro-polarimeter using photonic integrated circuits

The disclosed embodiments provide a method for integrating an optical interposer with one or more electronic dies and an optical-electronic (OE) printed circuit board (PCB). This method involves first applying surface-connection elements to a surface of the optical interposer, and then bonding the one or more electrical dies to the optical interposer using the surface-connection elements. Next, the method integrates the OE-PCB onto the surface of the optical interposer, wherein the integration causes the surface-connection elements to provide electrical connections between the optical interposer and the OE-PCB.

Optical-electrical interposers

The disclosed embodiments relate to the design of an optical phased array grating. This optical phased array grating includes an optical waveguide comprising a first material having a uniform lateral width, wherein the first material confines the optical waveguide as the optical waveguide core. It also includes an overlay layer comprising a sequence of overlays made of a second material spaced across a top surface of the optical waveguide, wherein successive overlays in the sequence have continuously varying longitudinal duty cycles and continuously varying lateral widths between an input end and an output end of the overlay layer, and wherein the second material has a lower optical index than the first material. The optical phased array grating also includes a cladding layer comprised of a third material deposited over the overlay layer and the optical waveguide.

Chirped grating surface emitter with uniform power emission for beam-steering applications

An optical device is described. This optical device includes an electro-optical material having an X-cut, Y-propagate orientation. In particular, a Y crystallographic direction of the electro-optical material is parallel to an optical waveguide defined in the electro-optic material and an X crystallographic direction of the electro-optical material is parallel to a vertical direction of the optical device. By applying drive signals having an angular frequency to the electro-optic material, the optical device may perform modulation, corresponding to a traveling-wave configuration, of an optical signal based at least in part on the drive signals. where the modulation involves a polarization conversion and a frequency shift. The angular frequency of the drive signals may be selected to approximately cancel electro-optic cross terms in X-Z plane of the electro-optical material. Moreover, an amplitude of the drive signals may be selected so that the optical device emulates a half-wave-plate configuration.

Integrated polarization converter and frequency shifter

A system that performs heterodyne optical imaging across multiple platforms gathers an optical signal from an optical sensor at each of the multiple platforms. At the same time, an optical frequency comb local oscillator (LO) at each of the platforms generates a reference comb signal comprising a set of optical frequency comb lines at different frequencies, wherein each optical frequency comb LO is locked to a local atomic clock at each of the platforms. Next, a mixer, at each of the platforms, is used to mix the optical signal gathered from the optical sensor with the reference comb signal generated by the optical frequency comb LO to generate a mixed signal. The system then communicates the mixed signals generated at each of the platforms to a central location. Finally, the system correlates the mixed signals received from each of the platforms and generates a reconstructed optical image.

Achieving ultra-high resolution heterodyne synthetic imaging across multiple platforms using optical frequency comb sources

A method and system are described for reducing a thermo-optic effect in silicon photonics. In described embodiments, the system comprises a silicon photonic device with a silicon core that includes a cladding layer comprising titanium adjacent to the silicon core. In described embodiments, the method comprises providing a silicon core and depositing a cladding layer adjacent to the silicon photonic core, wherein the cladding layer comprises titanium.

Reduction of thermo-optic effects in silicon photonics

A network configuration provides arbitration-free all-to-all connection between the nodes of the network utilizing wavelength routing devices and utilizing a limited number of wavelengths for routing optical signals to the nodes of the network.

Limited wavelength all-to-all wavelength routing network configuration

An edge router for interfacing an optical label switched core IP network with client networks, which may be electronically switched and operate with different protocol. The core network has a limited number of ports, each with an edge router, which receives packets from one or more associated client networks and queues them according to egress port on the core network and optionally additionally according to attribute of service. When a queue has exceed a maximum packet length or a timeout limit assigned to the queue, the packets including their headers are assembled into a super packet for transmission across the core network in optical form, preferably using optical routers incorporating wavelength conversion of payloads and switching according to an attached label. The edge router at the egress port disassembles the super packet into constituent packets for respective destinations on the client network.

Edge router for optical label switched network

An all-optical regenerating circuit including a wavelength converter based on a Mach-Zehnder interferometer. The input signal is amplified and the interferometer adjusted to place the input signal across an entire monotonic portion of a sinusoidal transfer function to the wavelength-converted output signal. Retiming is effected by wavelength converters including pulsed laser sources of the output wavelength. A multi-wavelength regenerator may be integrated on a chip including two arrayed waveguides and an array of tunable lasers on parallel waveguides therebetween.

Reconfigurable multi-channel all-optical regenerators

An optical code-division multiple-access (O-CDMA) apparatus, network, and communications method. A transmitter data modulates a sequence of ultra-fast (&#x2dc;1 ps) pulses. An encoder wavelength demultiplexes the pulses, separately phase-modulates the wavelength components according to a first CDMA code and wavelength multiplexes for transmission on an optical network. A receiver includes a decoder performing similar demultiplexing, phase-modulating according to a second CDMA code, and multiplexing. The receiver detects the resultant signal. If the two CDMA codes match, the detected signal replicates the data-modulated pulses. The apparatus may be formed in as few as one substrate. The encoder/decoder structure may be used to compensate the dispersion of a fiber. A short-pulse detector includes a Mach-Zehnder interferometer having two semiconductor amplifier regions in its two arms with differential delay/phase between them. A probe signal and the signal to be detected are both split into the arms together and thereafter differenced on the output.

Growing community of inventors

Davis, CA, United States of America

Sung-Joo Ben Yoo