International Business Machines Corporation

Cornell University

William P Risk, Iii

Dharmendra S Modha

John Vernon Arthur

Paul A Merolla

Rajit Manohar

Alyosha C Molnar

William J Kozlovsky

Filipp A Akopyan

Wilfried Lenth

Christoph S Harder

Gary C Bjorklund

Heinz P Meier

Franklin M Schellenberg

Jean-Claude J Baumert

An event-driven neural network including a plurality of interconnected core circuits is provided. Each core circuit includes an electronic synapse array that has multiple digital synapses interconnecting a plurality of digital electronic neurons. A synapse interconnects an axon of a pre-synaptic neuron with a dendrite of a post-synaptic neuron. A neuron integrates input spikes and generates a spike event in response to the integrated input spikes exceeding a threshold. Each core circuit also has a scheduler that receives a spike event and delivers the spike event to a selected axon in the synapse array based on a schedule for deterministic event delivery.

Neuromorphic event-driven neural computing architecture in a scalable neural network

An event-driven neural network includes a plurality of interconnected core circuits is provided. Each core circuit includes an electronic synapse array has multiple digital synapses interconnecting a plurality of digital electronic neurons. A synapse interconnects an axon of a pre-synaptic neuron with a dendrite of a post-synaptic neuron. A neuron integrates input spikes and generates a spike event in response to the integrated input spikes exceeding a threshold. Each core circuit also has a scheduler that receives a spike event and delivers the spike event to a selected axon in the synapse array based on a schedule for deterministic event delivery.

A laser system uses a nonlinear crystal ring resonator to produce Type II nonlinear second harmonic generated light. The reflective surfaces of the resonator are oriented to form two closed beam paths for the two fundamental frequency light beams having different orthogonal polarization. The two beam paths overlap along one segment which is parallel to an axis of the nonlinear crystal. Second harmonic generated light is produced along this segment of the beam paths.

Laser system and method having a nonlinear crystal resonator

A first section of a waveguide channel is made of a nonlinear crystal material. A second section of the waveguide has a plurality of diverging channels. Each of the diverging channels is of a width which supports one of the modes of second harmonic generated light from the first section. First order mode second harmonic light is obtained at the end of one of the diverging channels.

First order mode frequency doubler system and method

A laser system uses a nonlinear ring resonator to produce Type-II nonlinear second harmonic generated light. The reflective surfaces of the resonator are all symmetrical with respect to the crystal axes. This allows orthogonally polarized light to be resonated along the same beampath in the resonator without experiencing bireflection.

Laser system and method

Pump laser light is focused into a solid state laser material. A resonator is positioned around the laser material. The resonator is comprised of reflectors which have high reflectivity at both the pump light frequency and the solid state laser light frequency. The resonator is impedance matched to the pump laser. The pump light resonates inside the solid state laser material until practically all of it is absorbed.

Passive absorptive rensonator laser system and method

Apparatus and method for producing coherent blue-green-light radiation having a wavelength of essentially 490-500 nm. A diode laser, such as a strained-layer InGaAs/GaAs diode laser, provides a 980-1,000 nm beam, and a nonlinear crystal of KTP produces coherent radiation by noncritically phase-matched second-harmonic generation (SHG) of said beam. The beam preferably has a wavelength of essentially 994 nm for generating radiation having a wavelength of essentially 497 nm. The crystal is disposed within an optical resonator and the frequency of the laser is locked to that of the resonator. Alternatively, two diode lasers are oriented to provide orthogonally polarized beams each with a wavelength of 980-1,000 nm but within essentially 1 nm of each other, and the KTP crystal is oriented with its a- and c-axis parallel to the orthogonally polarized beams. The KTP crystal may have an associated optical waveguide along which the beam is propagated to enhance SHG efficiency.

Miniature blue-green laser source using second-harmonic generation

Passive absorptive resonator laser system and method

A laser diode with a low reflectivity output facet provides infrared light to a nonlinear crystal resonator such that a portion of the infrared light is converted to blue light. A mirror is located on the opposite side of the nonlinear crystal resonator from the laser. The mirror allows the blue light to pass, but reflects the infrared light exiting the resonator back through the resonator and into the laser diode. The laser diode is thereby locked at the resonance frequency of the nonlinear crystal resonator.

Laser system and method using a nonlinear crystal resonator

A process and apparatus are disclosed for producing a beam of coherent radiation at essentially 459 nm by mixing, in a nonlinear crystal consisting essentially of KTP, two laser beams, one at essentially 1064 nm and the other at essentially 808 nm. The 1064 nm radiation is derived from a Nd:YAG laser that consists of an input mirror, an output mirror and a Nd:YAG crystal, and contains also the KTP crystal. The Nd:YAG laser is pumped by an essentially 808 nm semiconductor diode laser beam, which passes through the input mirror and through the KTP crystal into the Nd:YAG laser crystal where it is absorbed. The 1064 nm radiation oscillating inside the Nd:YAG laser resonator is mixed either with the said 808 nm pump beam or with 808 nm radiation provided by a second semiconductor diode laser whose light is coupled with the 1064 nm beam using a beamsplitter. The essentially 459 nm beam passes through the output mirror to a utilization device.

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Mountain View, CA, United States of America

William P Risk, Iii