United States of America As Represented by the Secretary of the Air Force

Sperry Corporation

Sperry Rand Corporation

USA As Represented by Secretary of the Navy

University of Delaware

Richard A Soref

Joseph P Lorenzo

Donald H McMahon

Lionel R Friedman

Andrew C Yang

Dennis W Prather

Brent Everett Little

Henry F Taylor

John Kouvetakis

Harry Kroger

Ahmed Sharkawy

Fereydoon Namavar

William B Spillman, Jr

Jose Menendez

Henry Zmuda

Shouyun Shi

Lloyd R Schissler

Gregory Sun

Norman A Sanford

Richard Payne

Stephen J Emelett

An optical signal low energy method for coupling electrical signals on-chip between component circuits of for example a CMOS circuit array. The described coupling method employs infrared signals communicated along a nano-scale resonant semiconductor waveguide between for example PIN diode signal transducers. The coupling may employ an electrically pumped laser, an electro absorption modulator and a photodetector all for typically the 1.5 to 2.0 micrometer spectral region with each formed using for example PIN heterodiode semiconductor devices. Each of these three devices includes active semiconductor crystal material situated in a resonator within a strip waveguide. The resonator is defined by two fabricated mirrors having a tapered location one dimensional photonic crystal lattice of oxide hole or slot apertures. Each semiconductor device is for example a heterodiode pumped or controlled by laterally disposed wings enclosing the resonator to form a lateral PIN structure for current injection or high E-field generation. CMOS compatible ten gigabit per second signals of low energy use per transmitted bit are achieved.

Semiconductor photonoic nano communication link method

A CMOS compatible ten-gigabit-per-second region nano-waveguide included photonic communication link apparatus of low energy use per transmitted bit. An embodiment of the link includes an electrically pumped laser, an electro absorption modulator and a photodetector for the 1.5 to 2.0 micrometer infrared spectral region; omission of the separate electro absorption modulator is additionally disclosed. Each of these three nano-scale elements preferably includes active semiconductor crystal material situated in a preferably Silicon resonator within a nano-strip waveguide. The resonator is defined by dispersed resonator mirrors having tapered separation distance one dimensional photonic crystal lattice apertures of oxide holes or slots. Each of the three devices may be a semiconductor heterodiode pumped or controlled by laterally disposed wings enclosing the resonator to form a lateral PIN heterodiode for current injection or high E-field generation depending on bias and composition conditions selected.

Semiconductor photonic nano communication link apparatus

An electro-optical switch implemented in coupled photonic crystal waveguides is disclosed. The switch is proposed and analyzed using both a finite-difference time-domain ('FDTD') method and a plane wave expansion ('PWM) method. The switch may be implemented in a square lattice of silicon posts in air, as well as in a hexagonal lattice of air holes in a silicon slab. Switching occurs due to a change in the conductance in the coupling region between the photonic crystal waveguides, which modulates the coupling coefficient and eventually causes switching. Conductance may be induced electrically by carrier injection or optically by electron-hole pair generation. The electro-optical switch has low insertion loss and optical crosstalk in both the cross and bar switching states.

Electro-optical switching using coupled photonic crystal waveguides

An electrically pumped semiconductor laser is provided as including a waveguide structure disposed on the substrate. An optical coupling layer is disposed on the substrate and the waveguide. A resonator layer is disposed on the optical coupling layer and may be adapted to include a photonic crystal lattice having a plurality of substantially cylindrical pores extending downwardly into the resonator layer. An insulating cap layer may be disposed on the resonator layer which operatives to seal the photonic crystal lattice. A first plug filled vias is formed on a central region of the cap layer, which extends downwardly to permit a bottom portion of the first plug to communicate with the photonic crystal lattice. Further, a second plug filled vias is formed on an edge region of the cap layer and extends downwardly to permit a bottom portion of the second plug to communicate with the photonic crystal lattice.

Electrically pumped Group IV semiconductor micro-ring laser

This invention teaches two new families of Si-based Ge/SnGeheterodiode and multiple quantum well (MQW) photonic devices: (1) band-to-band photodetectors, lasers, emitters, amplifiers and modulators for the 1.5 to 12 &#x3bc;m wavelength range; (2) intersubband photodetectors, lasers, emitters and modulators for 12 to 100 &#x3bc;m operation. The bipolar band-to-band devices have applications within the 1.5-2.2, 3-5 and 8-to-12 &#x3bc;m bands. The unipolar intersubband group has longwave infrared and terahertz applications. All strained-layer devices are grown a relaxed SnSiGebuffer layer&#x2014;a virtual substrate (VS) grown directly upon a silicon wafer by unique LT UHV-CVD. The VS provides a low-defect atomic template for subsequent heteroepitaxy and is an essential enabling technique for engineering tensile and compressive strain within the Ge/SnGeMQW by selecting the VS lattice parameter to be approx midway between the layer lattices.

Strain-engineered direct-gap Ge/SnxGe1-x heterodiode and multi-quantum-well photodetectors, laser, emitters and modulators grown on SnySizGe1-y-z-buffered silicon

The first phonon-pumped semiconductor laser. The active region is an unbiased boron-doped Si Ge /Si superlattice with Si Ge buffer layers embedded in a surface-plasmon strip waveguide. Warm and cool heat sinks create a temperature gradient across the waveguide. A heat buffer layer adjacent to the cool sink reflects optical phonons and transmits acoustic phonons. Within the resonator, the difference in effective temperatures of optical and acoustic phonons provides hole pumping for the lasing transition between the heavy-hole (HH ) and heavy-hole (HH ) minibands. A gain of 280/cm at the 5THz emission frequency is predicted for 6&times;10 /cm doping at temperatures of 300K and 77K for optical and acoustic phonons, respectively.

Phonon-pumped semiconductor lasers

Large-scale switching array architectures for multiwavelength routing employ absorption-switched micro-ring resonator 2&times;2 switches at all optical cross-points of each of a plurality of series-connected waveguide crossbar matrix switches. The architecture eliminates detrimental waveguide crossovers. Two or four coupled micro-rings made from layered III-V or II-VI hetrostructure material can aid in maintaining cross-talk at very low levels while employing simple switch addressing methods.

Wavelength-division multiplexed M&times;N&times;M cross-connect switch using active microring resonators

A family of lasers is provided which can be readily grown upon silicon wafer platforms, each laser having a highly doped stably strained SiGe or Ge collector layer formed upon a SiGe graded relaxed buffer layer in turn grown on the Si wafer, and an intrinsic strain-symmetric Ge--Si superlattice covered by a heavily doped stably strained SiGe emitter. The superlattice has numerous thin 8-15 atomic monolayers of interleaved Ge and Si atoms, enabling high stack heights.

Silicon-based strain-symmetrized GE-SI quantum lasers

A one-laser technique for optical time-delay beamsteering of a microwave phased-array antenna in transmit-and- receive modes. Arrays of reflective, fiber Bragg gratings are employed and a modulated, wavelength-tuned laser excites prism-shaped arrays of chirped or single-frequency gratings deployed inside a set of N parallel fibers. The fiber gratings can be replaced by waveguided gratings within a semiconductor chip for operation at high microwave frequencies.

Photonic time-delay beamsteering system using fiber bragg prism

A low-cost Si-based construction for optical and electronic bulk-heterostructure devices and multiple-quantum-well devices in which the active layers of the device are SiC or AlGaN or InGaN or InAlN. Material quality is high, and the MQW devices such as blue light lasers or LEDs have stable pseudomorphic layers with low defect densities. The low-cost large-area 3C SiC substrate is created by converting 100% of a 100-500 angstrom (.ANG.) layer of Si in a silicon-on-insulator wafer to 3C SiC with propane at 1300 degrees C. The SiO2 layer provides strain-free support for the 'perfect' 3C SiC crystal layer. Direct-gap wurtzite nitride heterostructures, bulk or pseudomorphic MQW, are grown upon an (0001) 6H SiC epilayer on the (111) 3C SIC substrate, or directly upon the (111) 3C SiC substrate. For zincblende heterostructures, a (100) 3C SiC substrate is used.

SiC/111-V-nitride heterostructures on SiC/SiO.sub.2 /Si for

Nanometer scale silicon-on-insulator (SOI) guided-wave optical components in the near infra-red employ an SOI platform for optical isolation, and single mode silicon strip etched into the buried oxide. A multi-layer core for the strip consistes of several 1-3 nanometer crystal silicon multiple quantum wells confined by wide bandgap epitaxial barriers. The MQW region of the strip employs intersubband or band-to-band photonic effects. Active strip microcavities use a photonic bandgap resonator of etched air cylinders, or two sets of etched slot Bragg grating reflectors. Many thousands of these components can be integrated on a Si chip.

Nanometer-scale silicon-on-insulator photonic componets

Silicon-based laser diodes, optical amplifiers, electrooptical modulators, and photodetectors in which the active region consists of a pseudomorphic GeSn multiple quantum well stack. Each quantum well is tensile-strained Ge.sub.1-x Sn.sub.x layer sandwiched between compressively strained barriers of Ge.sub.1-y Sn.sub.y with x.about.0.1, x&lt;y and y.about.0.15. The GeSn quantum wells have a strain-induced direct gap for strongly allowed band-to-band transitions in the infrared range. The quantum well stack is grown upon a relaxed SiGeSn alloy buffer portion whose composition is graded up from a lattice match at the silicon substrate interface to a Ge or GeSn composition at buffer's top surface. Doped cladding layers are added, so that the devices have a p-i-n diode structure. The monolithic integrated Column IV devices have a rib waveguide structure, where desired, and operate typically in the 2 to 3 micron wavelength range.

Direct-gap germanium-tin multiple-quantum-well electro-optical devices

The invention comprises processes and heterostructure products defining silicon on insulator waveguides (80, 88, 90, 106, 112, 120, 122) that are suitable for use with light in the 1.3, 1.6 .mu.m or greater wavelengths. Silicon is deposited on an insulator layer 12 on a crystalline substrate 10 and grown or regrown in crystalline form. The silicon is then etched or formed into a waveguide structures.

Method of making a lattice mismatched heterostructure optical waveguide

Lattice mismatched hetrostructure optical waveguide

A crystalline silicon 1.1-20 micron spatial light modulator has an X-Y array of p-i-n pixels which are selectively foward biased at low voltages to induce substantial phase shifts in the optical wavefront, by the dual injection of holes and electrons through the silicon body and parallel to the light being modulated. The easy-to-fabricate SLM, is less sensitive to changes in temperature and wavelength, and can modulate light regardless of its state of polarization.

Growing community of inventors

Newton Centre, MA, United States of America

Richard A Soref