Abstract: An ultralow-energy electro-optical 2×2 cross-bar switch comprises an identical pair of semiconductor nanobeams that are incorporated in the central arms of a waveguided Mach-Zehnder interferometer. Each nanobeam includes a one dimensional “lattice” of holes along the nanobeam axis that defines a resonant cavity whose fundamental mode is the operating wavelength of the switch. A localized, lateral lengthwise extending portion of the semiconductor nanobeam is doped P type, while the other lateral half of the nanobeam wing is doped N type, forming a P-N junction in the body. Application of an electric potential across the P-N junction alters the effective index of refraction of the lengthwise extending portion and controls both the transmission and reflection of an incoming optical signal at the operating wavelength of the switch through the semiconductor nanobeam. Constructive and destructive interference of component signals within the interferometer controls the spatial routing of the incident light.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: This invention teaches two new families of Si-based Ge/SnxGe1-x heterodiode and multiple quantum well (MQW) photonic devices: (1) band-to-band photodetectors, lasers, emitters, amplifiers and modulators for the 1.5 to 12 ?m wavelength range; (2) intersubband photodetectors, lasers, emitters and modulators for 12 to 100 ?m operation. The bipolar band-to-band devices have applications within the 1.5-2.2, 3-5 and 8-to-12 ?m bands. The unipolar intersubband group has longwave infrared and terahertz applications. All strained-layer devices are grown a relaxed SnySizGe1-y-z buffer layer—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/SnxGe1-x MQW by selecting the VS lattice parameter to be approx midway between the layer lattices.

Abstract: The first phonon-pumped semiconductor laser. The active region is an unbiased boron-doped Si0.94Ge0.06/Si superlattice with Si0.97Ge0.03 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 2 (HH2) and heavy-hole 1(HH1) minibands. A gain of 280/cm at the 5THz emission frequency is predicted for 6×1017/cm3 doping at temperatures of 300K and 77K for optical and acoustic phonons, respectively.

Abstract: Large-scale switching array architectures for multiwavelength routing employ absorption-switched micro-ring resonator 2×2 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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<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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Electrically controlled Fabry-Perot resonator elements are created in a semiconductor channel waveguide by etching two in-channel mirror facets (slots) and by positioning the resulting resonator core in the midregion of a P-I-N diode or field-effect transistor. A large number of FPs can be built monolithically on one semiconductor chip, with FPs connected by on-chip passive waveguides used for multiple on-chip time delays. The low-loss chips are coupled efficiently in end-fire fashion to a group of optical fibers that comprise the optical signal processing system. III-V quantum-well, superlattice, and n-i-p-i materials are preferred for the semiconductor devices, and a variety of electrooptical effects are available for use, including the quantum-confined Stark effect, phase-space absorption quenching, Wannier-Stark effect, plasma dispersion effect, and band-flattening.

Abstract: Phase enhancement by resonant Fabry-Perot picture elements in III-V semiconductor spatial light modulators (SLMs) is disclosed. For 95% reflecting electrodes, a phase modulation of 0.7.pi. rad is found in transmission when the electrooptic input phase is 0.06.pi. rad. A resonant phase-dominant SLM in a 1.7-.mu.m-thick AlGaAs/GaAs multiple quantum well (MQW) structure can employ field effects and carrier-induced electrooptic effects within the MQWs.

Abstract: A tiny, high speed, low cost electrooptic switch is provided having co-planar waveguides of silicon oxynitride and a ferro-electric liquid crystal layer overlying the waveguides. A voltage source causes the molecular optic axis of the liquid crystal to rotate 45-90 degrees within the plane of the liquid crystal layer to cause a change of state of the switch.