Abstract: A photonic crystal waveguide apparatus has a photonic crystal having a waveguide which is capable of transmitting light having a frequency within a bandgap of the photonic crystal, and a resonant stub connected to the waveguide to control light in the waveguide. The resonant stub has a resonator region and a connecting channel which connects the resonator region to the waveguide. The resonant stub controls light transmission characteristics of the waveguide by creating a transmission zero in the transmission band of the waveguide. A tuner for tuning the resonant stub may also be provided to control the transmission zero to provide an active optical apparatus such as an on/off switch or a modulator.

Abstract: Optically resonant systems for redirecting optical signals are provided. A representative optically resonant system includes a first structure in a plane. The first structure reflects optical radiation in a first direction substantially orthogonal to the plane. The optically resonant system further includes a second structure overlapping the first structure. The second structure optically communicates with the first structure, and reflects optical radiation substantially parallel to the plane. The first and second structures operate to capture at least a portion of a first optical signal propagating substantially parallel to said plane by exciting a resonant signal in the resonant cavity through the resonant characteristics of the first and second structures. The first and second structures further operate to emit said resonant signal in a second direction substantially orthogonal to said plane. Methods and other optically resonant systems also are provided.

Abstract: Two-dimensional photonic crystal slab apparatus and a method for fabricating two-dimensional photonic crystal slab apparatus. A two-dimensional photonic crystal slab apparatus has a photonic crystal slab containing a two-dimensional periodic lattice, and upper and lower cladding layers for the photonic crystal slab, the upper and lower cladding layers each having a metallic cladding layer. The metallic cladding layers permit achieving substantially perfect light transmission through a waveguide in the slab, even when the waveguide is strongly bent. The fabrication method includes forming a two-dimensional photonic crystal slab from a dielectric slab supported on a substrate by, for example, an etch process.

Abstract: A photonic crystal waveguide apparatus has a photonic crystal having a waveguide which is capable of transmitting light having a frequency within a bandgap of the photonic crystal, and a resonant stub connected to the waveguide to control light in the waveguide. The resonant stub has a resonator region and a connecting channel which connects the resonator region to the waveguide. The resonant stub controls light transmission characteristics of the waveguide by creating a transmission zero in the transmission band of the waveguide. A tuner for tuning the resonant stub may also be provided to control the transmission zero to provide an active optical apparatus such as an on/off switch or a modulator.

Abstract: Two-dimensional photonic crystal slab apparatus and a method for fabricating two-dimensional photonic crystal slab apparatus. A two-dimensional photonic crystal slab apparatus has a photonic crystal slab containing a two-dimensional periodic lattice, and upper and lower cladding layers for the photonic crystal slab, the upper and lower cladding layers each having a metallic cladding layer. The metallic cladding layers permit achieving substantially perfect light transmission through a waveguide in the slab, even when the waveguide is strongly bent. The fabrication method includes forming a two-dimensional photonic crystal slab from a dielectric slab supported on a substrate by, for example, an etch process.

Abstract: A quantum wire switch and a switching method for switching charge carriers between a first output and a second output utilizing quantum interference of the charge carriers. A quantum switch includes a quantum wire extending from an input to a first output, a second quantum wire extending from the input to a second output, and a third quantum wire extending between the first and second outputs, the three quantum wires together defining a ring. A controllable-length quantum wire electron stub tuner is connected to the ring. As charge carriers propagate from the input around the ring the stub tuner is used to control the quantum interference of the charge carriers resulting in local maxima and minima at various points around the ring. Setting the stub to a first length results in a local maximum at the first output and a local minimum at the second output, and the charge carriers can propagate to the first output and not the second output.

Abstract: A quantum wire switch and a switching method for switching charge carriers between a first output and a second output utilizing quantum interference of the charge carriers. A quantum switch includes a quantum wire extending from an input to a first output, a second quantum wire extending from the input to a second output, and a third quantum wire extending between the first and second outputs, the three quantum wires together defining a ring. A controllable-length quantum wire electron stub tuner is connected to the ring. As charge carriers propagate from the input around the ring the stub tuner is used to control the quantum interference of the charge carriers resulting in local maxima and minima at various points around the ring. Setting the stub to a first length results in a local maximum at the first output and a local minimum at the second output, and the charge carriers can propagate to the first output and not the second output.

Abstract: A mass spectrometer is disclosed which yields fast, full-scan spectra over a wide mass-to-charge ratio range. The instrument contains an ion source which generates nearly monoenergetically-pulsed ion packets which spatially focus at a predetermined distance along the drift path of the ions, a mass filter/analyzer which linearly disperses or deflects the ions in the ion-packets by mass-to-charge ratio by applying a traverse, quadratically time-varying and increasing electric field over the entire length of the deflection region of the mass filter/analyzer, and a spatial mass detector. A method of analyzing the mass-to-charge ratio of ions is also disclosed.

Abstract: A simplified apparatus and a design method for providing microwave resonators having high Q factors. The apparatus includes a resonant microwave cavity having three mutually orthogonal dimensions and a low loss dielectric body substantially enclosing each dimension of the resonant microwave cavity. To further increase Q-factor, the apparatus of the invention preferably includes a plurality of resonant microwave cavities and a plurality of low loss dielectric bodies each substantially enclosing a respective one of the microwave resonant cavities. In some embodiments the low loss dielectric bodies are arranged in a stack. In other embodiments the low loss dielectric bodies are concentrically arranged.

Abstract: A notch filter for selectively removing a target ion with a specific mass-to-charge ratio from an ion beam is provided. The notch filter uses a quadrupole and a power supply for generating an rf electrical potential in the quadrupole. The quadrupole has two pairs of parallel electrodes of opposite polarities. Each pair is comprised of two parallel electrodes having equal electrical potential. The rf electrical potential generated by the power supply is a superposition of an rf quadrupole frequency component and an excision frequency component. The quadrupole has an inlet end and an outlet end and the ion beam traverses from the inlet end to the outlet end. As a result of the rf quadrupole frequency component, ions of above a selected mass-to-charge ratio are guided down the quadrupole. The excision frequency component, which is at the second harmonic of the dominant resonant frequency of the target ion, causes the target ion to resonate and be removed from the ion beam before exiting the quadrupole.

Abstract: A multinotch filter for selectively removing target ions with a plurality of specific mass-to-charge ratios from an ion beam is disclosed. The multinotch filter uses a quadrupole and a power supply for generating rf voltages in the quadrupole. The quadrupole has two pairs of parallel electrodes. Each pair has two parallel, oppositely facing electrodes. The rf voltages generated by the power supply includes a rf quadrupole frequency component and at least a first excision frequency component and a second excision frequency component. The rf quadrupole frequency component is applied to the electrodes such that within each pair the two oppositely facing electrodes with respect to the rf quadrupole frequency component are equal in potential and the two pairs are 180.degree. out of phase. With respect to the first excision frequency component, the oppositely facing electrodes within one pair are 180.degree. out of phase with each other.

Abstract: A fluid sensing device such as a Surface Transverse Wave device or a Love Wave device having controlled transfers of energy from a transduction surface of a piezoelectric substrate to a sensing surface and back to the transduction surface. A first wave-trapping structure adjacent to an input transducer tapers to provide a controlled diffraction of shear transverse wave energy to a second wave-trapping structure disposed on an opposite side of the piezoelectric substrate. The second wave-trapping structure interfaces with the fluid under test. The shear transverse waves are then recaptured by a third wave-trapping structure on the same surface as the first wave-trapping structure. The wave energy is then decoupled from the piezoelectric substrate. In the STW device, the wave-trapping structures are periodic fingers that are selectively varied in thickness or width or both. In the LW device, the wave-trapping structures are plates that each vary in thickness.

Abstract: A sensor suitable for use as a viscosity sensor, a chemically selective sensor, or a chemically specific sensor. The sensor is a surface transverse wave (STW) or Love Wave device that, for solute concentration measurements, includes a chemically reactive layer selected to react with the solute to be measured. The surface trapping structure in this device can include dielectric material either as a protective coating or as the core material of the surface trapping structure. The substrate material and cut are selected so that only shear horizontal acoustic waves are produced. Nonpiezoelectric portions of this device can be utilized in the region in which chemicals react the sensor and/or in the region in which energy is converted between electrical and acoustical forms.

Abstract: A shear transverse wave device having transitions in the relaxation or tightening of wave trapping. Two embodiments are preferably utilized simultaneously. A first embodiment involves wave trapping fingers disposed within a propagation region between a transmitting and a receiving interdigital transducer. The wave trapping fingers provide a high width-to-spacing ratio of fingers proximate to the transducers and provide a lower ratio with approach to a center of the propagation region. The relaxed trapping reduces the adverse effects caused by surface perturbations, while the tight trapping at the transducers provides an efficient coupling of power to and from the device. The second embodiment is likewise concerned with decoupling of power. Absorptive film is placed at the opposed edges of the device to suppress spurious reflections from the edges.

Abstract: A fluid sensing device such as a Shear Transverse Wave device or a Love Wave device having a wave-trapping structure that provides tight surface trapping at transduction and sensing regions, but permitting a deeper penetration of wave energy at the interface of a seal with the wave-trapping structure. In the STW device, wave-trapping fingers are selectively varied in thickness, width or both to achieve the selective trapping. In an LW device, a wave-trapping plate is reduced in thickness at seal regions.

Abstract: A sensor (11, 12, 13, 15) suitable for use as a viscosity sensor, a chemically selective sensor, or a chemically specific sensor. The sensor (11, 12, 13, 15) is a surface transverse wave (STW) device that, for solute concentration measurements, includes a binding layer (18) selected to bind to the solute to be measured. This binding layer (18) can be an antibody so that the sensor detects a particular antigen.