Abstract: A one-way reflective sensor shield with an increased bandwidth meta-materials coating is provided which substantially reduces or eliminates deleterious electronic signatures and backscattering. The one-way reflective sensor shield with meta-materials coating operates according to surface plasmonic coupling phenomena and achieves a mirror-like one-way reflection of electromagnetic signals. In this arrangement, the meta-materials coating is composed of a dielectric material, and the corrugated metal strips are composed of a metallic conductive material with a negative dielectric constant, to allow surface plasmonic coupling between the plasma in the metal and the incident electromagnetic field. Surface plasmons occur at the interface of a material with a positive dielectric constant, such as dielectric surface, with that of a negative dielectric constant, usually a metal or doped dielectric, such as the metal strips. Sensor devices and sensor shielding systems are also provided.

Abstract: The present invention provides a device for frequency-selective detection of electromagnetic radiation in the terahertz region of the electromagnetic spectrum using a lateral semiconductor superlattice, a metal antenna attached to the lateral semiconductor superlattice; and a resonator comprising two mirrors and a substrate. A method for detecting electromagnetic radiation using the device is also provided.

Abstract: RF programmable SAW filters achieve selectable filter performance by providing tunable input and output interdigital (IDTs) with different synchronous frequencies and substantially reduce electromagnetic interference (EMI) associated with RF signals not of interest. The RF programmable SAW filter includes tunable input and output IDT's, with the input and output IDT's having different input and output IDT synchronous frequencies. The input signal is divided into multiple output signals along multiple signal paths that are applied to an input tap weight network wherein the amplitude of each output signal may be varied individually. The individually weighted signal paths are then applied one each to individual IDT input electrode fingers in a means for IDT input, which is characterized by a synchronous frequency Fin. The IDT input means generates an acoustic wave that propagates to a means for IDT output, which is characterized by a synchronous frequency Fout, where Fin and Fout are not the same.

Abstract: Fiber Bragg gratings (FBG) seismic activity sensors coupled in sensor arrays provide increased sensitivity to seismic activities, lower strain values and an absence of EMI allowing detection of troop and vehicle movements based on ground vibrations generating seismic signals. The FBG sensor head features a spring-mass configuration with a head surface, fiber optic cable and the FBG sensor attached to a spring that stretches during the acceleration of the mass. Waves propagating inside the earth and along the ground arriving at the sensor locations cause movement of the seismic activity sensors embedded in the ground and this movement induces an acceleration-dependent change in the FBG gratings placed on the sensors. In multiple sensor configurations, the cable will be connected to the other sensors in the network. FBG sensors, sensor arrays and sensor methods are provided in several embodiments.

Abstract: An optical add-drop multiplexer comprises an optical switch (10) for selection of a desired wavelength channel to be extracted, a pre-processing channel assembly (20), an optical reflector (50), an optical extractor (60), a post-processing channel assembly (30), and an optical coupler (40) aligned with the post-processing channel assembly. The pre-processing channel assembly transmits a multiplexed signal stream containing a plurality of channels. The optical reflector directs light rays emitted from the pre-processing channel assembly into the optical extractor. The optical extractor comprises a narrow bandpass filter (62) that allows a desired channel to pass therethrough and reflects other unextracted channels. The desired channel can be dropped by switching to a corresponding output port of the optical switch. The optical reflector directs light rays reflected from the optical extractor to the post-processing channel assembly. The optical coupler combines the unextracted channels and an insertion channel.

Abstract: The present invention provides a device for frequency-selective detection of electromagnetic radiation in the terahertz region of the electromagnetic spectrum using a lateral semiconductor superlattice, a metal antenna attached to the lateral semiconductor superlattice; and a resonator comprising two mirrors and a substrate. A method for detecting electromagnetic radiation using the device is also provided.

Abstract: An optical add-drop multiplexer comprises an optical switch (10) for selection of a desired wavelength channel to be extracted, a pre-processing channel assembly (20), an optical reflector (50), an optical extractor (60), a post-processing channel assembly (30), and an optical coupler (40) aligned with the post-processing channel assembly. The pre-processing channel assembly transmits a multiplexed signal stream containing a plurality of channels. The optical reflector directs light rays emitted from the pre-processing channel assembly into the optical extractor. The optical extractor comprises a narrow bandpass filter (62) that allows a desired channel to pass therethrough and reflects other unextracted channels. The desired channel can be dropped by switching to a corresponding output port of the optical switch. The optical reflector directs light rays reflected from the optical extractor to the post-processing channel assembly. The optical coupler combines the unextracted channels and an insertion channel.

Abstract: Methods and apparatus for measuring the millimeter or submillimeter wave absorption spectra in a sample of DNA molecules are provided.

Abstract: The operational flexibility of programmable transversal filters is enhanced by incorporating switch arrays to permit passage for a plurality of tap voltages or signals to particular amplifiers in amplifier arrays. Fixed gain amplifiers may be incorporated to overcome the need to calibrate variable gain amplifiers and to reduced the number of amplifiers required.

Abstract: The present invention is achieved by layering a dielectric slab between a ground plane and a two dimensional quasi quantum well heterostructure and by switching between an unbiased state and a negative potential which is established between the quantum well heterostructure and the ground plane. In the unbiased state, the device supports wave propagation in the dielectric with a phase velocity similar to that of a wave propagating in a parallel plate waveguide. Upon application of the bias voltage, that is establishing a negative potential difference between contacts based on either side of the quantum well heterostructure, the conductivity of the quantum well decreases. Therefore, as the carrier wave propagates the wave interacts with a boundary similar to that of a dielectric-air interface. This new boundary condition, in turn, produces a faster phase velocity. Hence, toggling the bias modulates the quantum well conductivity which changes the phase velocity of the carrier wave.

Abstract: The invention is directed to resonators and more particularly to an MMIC-compatible resonator which can be fabricated on an MMIC chip using MMIC processing techniques. The MMIC-compatible resonator has a substrate approximately 100 microns thick made of semi-insulating GaAs and/or AlGaAs. The substrate flanks an air via on which is fabricated a thin film piezoelectric semi-insulating GaAs film, comprising the piezoelectrically active element. The piezoelectrically active element is flanked either laterally or from the top to bottom thereof by a pair of electrodes which serve to excite the thickness shear or thickness extensional mode of the thin film piezoelectrically active element. There are a number of III-V and II-VI binary compounds and ternary, and other piezoelectric semiconductor alloys, which can be used for the purposes of the invention. The thin film measures approximately 5 microns or less in thickness and is fabricated on the semi-insulating GaAs, on the ?110!, ?111! or ?100! axis thereof.