Abstract: An apparatus includes a substrate having a metallic surface, a structure, and a dielectric object facing the metallic top surface. The structure is configured to optically produce surface plasmon polaritons that propagate on the metallic surface. The dielectric object is controllable to adjust values of the dielectric constant at an array of different positions along and near to the metallic surface.

Abstract: A method for determining symbols PSK modulated on an optical carrier includes interfering a first polarization component of the modulated optical carrier and a reference optical carrier in a first optical mixer and interfering the first polarization component of the modulated optical carrier and the reference with a different relative phase in a second optical mixer. The method also includes sampling the interfered carriers from the first optical mixer to produce first digital sampled values and sampling the interfered carriers from the second optical mixer to produce second digital sampled values. The first and second digital sampled values of a sampling period form a first complex sampling value thereof. The method also includes offsetting a phase of a complex signal value corresponding to each first complex sampling value to correct for a phase error caused by a frequency offset between the modulated and reference optical carriers.

Abstract: A fabrication method produces a mechanically patterned layer of group III-nitride. The method includes providing a crystalline substrate and forming a first layer of a first group III-nitride on a planar surface of the substrate. The first layer has a single polarity and also has a pattern of holes or trenches that expose a portion of the substrate. The method includes then, epitaxially growing a second layer of a second group III-nitride over the first layer and the exposed portion of substrate. The first and second group III-nitrides have different alloy compositions. The method also includes subjecting the second layer to an aqueous solution of base to mechanically pattern the second layer.

Abstract: A method for operating an optical receiver includes at each of a sequence of sampling times, producing a first 2D complex digital signal vector whose first component is indicative of a phase and amplitude of one polarization component of a modulated optical carrier and whose second component is indicative of a phase and amplitude of another polarization component of the carrier. For each one of the sampling times, the method includes constructing a second 2D complex digital signal vector that is a rotation of the first 2D complex digital vector for the one of sampling times. The rotation compensates a polarization rotation produced by transmission of the modulated optical carrier between an optical transmitter and the optical receiver.

Abstract: One method configures an all-optical network such that at least eighty percent of optical fiber spans of a portion of a first all-optical path of the network have substantially a first residual dispersion per span and at least eighty percent of optical fiber spans of a remainder of the first all-optical path have residual dispersions per span substantially differing from the first residual dispersion per span. The remainder of the first all-optical path includes an overlap between the first all-optical path and a second all-optical path of the network. The second all-optical path has a plurality of optical fiber spans and a substantially singly periodic dispersion map.

Abstract: An apparatus includes a substrate with a planar surface, a multilayer of semiconductor layers located on the planar surface, a plurality of electrodes located over the multilayer, and a dielectric layer located between the electrodes and the multilayer. The multilayer includes a 2D quantum well. A first set of the electrodes is located to substantially surround a lateral area of the 2D quantum well. A second set of the electrodes is controllable to vary a lateral width of a non-depleted channel between the substantially surrounded lateral area of the 2D quantum well and another area of the 2D quantum well. A third set of the electrodes is controllable to vary an area of a non-depleted portion of the lateral area.

Abstract: An electro-mechanical actuator includes a comb drive and a deformable connector. The comb drive has a first capacitor plate and a second capacitor plate. The capacitor plates have teeth capable of inter-digitating. The deformable connector is configured to apply a mechanical restoring force to the first capacitor plate. The deformable connector is configured to restore the first capacitor plate to be at an equilibrium rest position in response to no control voltage being applied across the capacitor. The comb drive is more engaged at the equilibrium rest position than at a mechanical stability threshold of the comb drive. The capacitor plates are disengaged at the equilibrium rest position.

Abstract: An exemplary optical modulator includes an interferometer. The interferometer includes an input optical coupler, an output optical coupler, and two or more controllable optical waveguides. Each controllable optical waveguide connects the input optical coupler to the output optical coupler and has an electro-absorption modulator along a segment thereof. Two of the controllable optical waveguides are connected to transmit to an output of the output optical coupler light of substantially different maximum amplitude.

Abstract: An apparatus includes an electronic amplifier and an electrical feedback line, a plurality of electrical sources, and an electronic controller. The electrical feedback line connects an output of the electronic amplifier to an input thereof. The electrical sources connect to nodes on the electronic feedback line. The electronic controller is configured to adjust the electrical sources in a manner responsive to a current input to the electrical feedback line.

Abstract: An apparatus includes an optical resonator and a passive optical device. The optical resonator has first and second optical reflectors and an optical cavity interposed between the reflectors. The optical resonator includes an electro-optically responsive material. One of the reflectors is a distributed Bragg reflector. A passive optical device is configured to direct light through the first optical reflector. The optical resonator is configured to return a portion of the light through the first reflector.

Abstract: An apparatus includes a medium that is a metamaterial over a frequency range. The medium includes a stack of layers or slabs. A mechanical, electrical, or magnetic property of the layers or slabs of the stack varies monotonically between neighboring ones of the layers or slabs.

Abstract: An apparatus includes a transmitter configured to transmit symbols to one or more receivers via a plurality of communication channels of a physical communication link. The transmitter is configured to estimate a phase of one or more off-diagonal elements of a channel matrix for the physical communication link based on values of signal-to-interference-plus-noise ratios at the one or more receivers.

Abstract: A method involves performing a plurality of acts. The acts include transmitting a first signal stream to a first channel of a multi-channel communications medium while transmitting a second signal stream to a different second channel of the medium. The second signal stream is substantially temporally correlated to the first signal stream. The method includes receiving an SINR measured at a receiver configured to receive signals from the first channel. The SINR is measured while the receiver received the first signal stream. The method includes determining a channel matrix element between the first and second channels or a ratio of said channel matrix element to a diagonal element of the channel matrix. The act of determining is based on the received SINR.

Abstract: A method includes an act of providing a crystalline substrate with a diamond-type lattice and an exposed substantially (111)-surface. The method also includes an act of forming a graphene layer or a graphene-like layer on the exposed substantially (111)-surface.

Abstract: An apparatus includes a field-effect transistor (FET). The FET includes a region of first semiconductor and a layer of second semiconductor that is located on the region of the first semiconductor. The layer and region form a semiconductor heterostructure. The FET also includes source and drain electrodes that are located on one of the region and the layer and a gate electrode located to control a conductivity of a channel portion of the semiconductor heterostructure. The channel portion is located between the source and drain electrodes. The gate electrode is located vertically over the channel portion and portions of the source and drain electrodes.

Abstract: A method includes receiving a request for admission of a new communications session to a data network. The requested admission is such that the new communications session is granted a first set of one or more bandwidth usages of a resource of the network in response to being admitted. Each of one or more admitted communications sessions concurrently has a granted set of one or more bandwidth usages of the resource. The method includes admitting the new communications session to the data network in response to a sum over each set of the largest bandwidth usage of the resource in the each set being larger than an effective input bandwidth of the resource. Each admitted communications session is able to access a bandwidth of the resource up to any of the one or more bandwidth usages in its own one of the sets.

Abstract: A method for operating an optical receiver includes at each of a sequence of sampling times, producing a first 2D complex digital signal vector whose first component is indicative of a phase and amplitude of one polarization component of a modulated optical carrier and whose second component is indicative of a phase and amplitude of another polarization component of the carrier. For each one of the sampling times, the method includes constructing a second 2D complex digital signal vector that is a rotation of the first 2D complex digital vector for the one of sampling times. The rotation compensates a polarization rotation produced by transmission of the modulated optical carrier between an optical transmitter and the optical receiver.

Abstract: An apparatus includes an object formed of a quasi-1D crystalline material that is capable of supporting a free sliding density wave state. The apparatus also includes first and second input terminals that connect across a portion of the object and first and second output terminals that connect across the same portion of the object.

Abstract: A field-effect transistor includes source, drain, and gate electrodes; a crystalline or polycrystalline layer of inorganic semiconductor; and a dielectric layer. The layer of inorganic semiconductor has an active channel portion physically extending from the source electrode to the drain electrode. The inorganic semiconductor has a stack of 2-dimensional layers in which intra-layer bonding forces are covalent and/or ionic. Adjacent ones of the layers are bonded together by forces substantially weaker than covalent and ionic bonding forces. The dielectric layer is interposed between the gate electrode and the layer of inorganic semiconductor material. The gate electrode is configured to control a conductivity of an active channel part of the layer of inorganic semiconductor.

Abstract: A solid structure includes a substrate and a layer located on a surface of the substrate. The layer includes crystalline or polycrystalline MgB2.