Abstract: An optical switch that includes optical paths organized into a set of M input optical paths and a set of N output optical paths. The optical switch additionally includes a faceted mirror corresponding to each of the M input optical paths and including N facets and a faceted mirror corresponding to each of the N output optical paths and including M facets. Finally, the optical switch includes a moving mechanism coupled to each faceted mirror to step the faceted mirror to selectively align one of the facets of the faceted mirror with the one of the optical paths with which the faceted mirror is associated. The facets of each of the faceted mirrors corresponding to one of the sets of optical paths, i.e., the set of input optical paths or the set of output optical paths, are preferably angled to reflect light towards a different one of the faceted mirrors corresponding to the other of the sets of optical paths, i.e., the set of output optical paths or the set of input optical paths, respectively.

Abstract: The optical switch comprises a substrate, a planar waveguide circuit, an index-matching liquid, a working fluid and a displacing device. The planar waveguide circuit is supported by the substrate. The planar waveguide circuit and the substrate collectively define a trench that includes a first trench region and a second trench region adjacent the first trench region. The second trench region has a width greater than the first trench region. The planar waveguide circuit includes a first waveguide and a second waveguide. The waveguides intersect at the first trench region and are positioned such that light traversing the first waveguide enters the second waveguide when an index-matching material is present in the first trench region, and is otherwise reflected by said the first trench region. The index-matching liquid is located in at least part of the first trench region. The working fluid is located in the second trench region.

Abstract: A digital pixel driver that operates in response to an M-bit digital input value defining the apparent brightness of the pixel. The pixel driver generates a pixel drive signal having a duty cycle that sets the apparent brightness of the pixel. The pixel driver comprises a memory, a digital sequence generator and a comparator. The memory receives and stores an N-bit word that represents the digital input value. The digital sequence generator generates a digital sequence of P-bit digital values that defines the temporal duration of the pixel drive signal and includes a first P-bit word that represents at least part of the digital input value at a location temporally corresponding to the duty cycle of the pixel drive signal as defined by the at least part of the digital input value. The comparator is connected to receive the digital sequence from the digital sequence generator and a second P-bit word from the memory. The second P-bit word constitutes at least part of the N-bit word.

Abstract: The ionospheric delay of a GPS signal transmitted by a first satellite having an obliquity is measured autonomously and substantially in real-time by receiving a code range, a carrier phase range and a satellite elevation angle for each of at least two satellites. For each of the at least two satellites, a code-phase divergence between the code range and the carrier phase range is calculated, an obliquity is calculated from the satellite elevation angle and time derivatives of the code-phase divergence and of the obliquity are calculated. A zenith delay is calculated from the obliquities, the time-derivatives of the obliquities and the time-derivatives of the code-phase divergences of the at least two satellites. The ionospheric delay is calculated by multiplying the obliquity of the first satellite and the zenith delay.

Abstract: A photoconductive relay that comprises a light-emitting device, a photoconductive switching element and columns of a conductive, fusible material. The light-emitting device and the photoconductive switching element respectively include including a light-emitting region and a light-receiving region. The columns extend between the light-emitting device and the photoconductive switching element to locate the light-emitting region of the light-emitting device opposite the light-receiving region of the photoconductive switching element and separated from one another by a distance of no more than 100 &mgr;m.

Abstract: The photoconductive switch comprises a first confinement layer, a second confinement layer, a photoconductive layer that includes a doped sub-layer and an undoped sub-layer, a first electrode and a second electrode. The first confinement layer is a layer of a first semiconductor material having a first band-gap energy and a first conductivity type. The second confinement layer is a layer of a second semiconductor material having a second band-gap energy. The photoconductive layer is a layer of a third semiconductor material having a third band-gap energy and a second conductivity type, opposite to the first conductivity type. The photoconductive layer is sandwiched between the first confinement layer and the second confinement layer, and the third band-gap energy is less than the first and second band-gap energies. In the photoconductive layer, the doped sub-layer is in contact with the first confinement layer, and the undoped sub-layer is adjacent the second confinement layer.

Abstract: A scan head that comprises an elongate light source, an elongate light sensor array and a planar waveguide array The light source is disposed perpendicular to the scan direction. The light sensor array is disposed parallel to the light source. The planar waveguide array includes an input end and an output end, and is curved about an axis parallel to the light source. The input end is located to receive light from the light source reflected by the object. The output end is located adjacent the light sensor array. The waveguide array includes tapered waveguides linearly arrayed in an array direction parallel to the light source. Each of the waveguides has a width in the array direction that decreases towards the output end of the waveguide array.

Abstract: A quantum absorber is provided having transitions that include a first transition between a first lower quantum state and an upper quantum state, and a second transition between a second lower quantum state and the upper quantum state. The first transition and the second transition have energies that correspond to frequencies of &ohgr;1 and &ohgr;2, respectively. The lower quantum states differ in energy by an energy difference subject to a total a.c. Stark shift. Incident electro-magnetic radiation is generated. The incident electro-magnetic radiation includes main frequency components and additional frequency components. The main frequency components are at frequencies of &OHgr;1 and &OHgr;2, equal to &ohgr;1 and &ohgr;2, respectively, and differ in frequency by a frequency difference. The additional frequency components collectively have a spectrum. The quantum absorber is irradiated with the incident electro-magnetic radiation.

Abstract: The frequency standard comprises a quantum absorber, source of incident electr-omagnetic radiation, detector, controller and signal output. The quantum absorber has a transition between a lower quantum state split by hyperfine interaction into two lower sub-state groups of at least one lower sub-state, and an upper quantum split by hyperfine interaction into upper sub-state groups of at least one upper sub-state. None of the upper sub-state groups is a cycling transition sub-state group having at least one allowed electric dipole transition to one lower sub-state group but none to the other. The upper quantum state differs in energy from a first lower sub-state in one of the lower sub-state groups and from a second lower sub-state in the other of the lower sub-state groups by energy differences that correspond to frequencies of &ohgr;1 and &ohgr;2, respectively.

Abstract: A detection signal that quantifies a resonant interaction between a quantum absorber and incident electro-magnetic radiation is generated. The quantum absorber is irradiated with the incident electro-magnetic radiation. The quantum absorber absorbs a portion of the incident electro-magnetic radiation and generates fluorescent electro-magnetic radiation in response to it. The quantum absorber additionally transmits the unabsorbed portion of the incident electro-magnetic radiation. The unabsorbed portion of the incident electro-magnetic radiation is detected to generate a first signal that has a first signal-to-noise ratio. The fluorescent electro-magnetic radiation is detected to generate a second signal that has a second signal-to-noise ratio. The first signal and the second signal are combined to generate the detection signal. The detection signal has a signal-to-noise ratio greater than the first signal-to-noise ratio and the second signal-to-noise ratio.

Abstract: The display device operates in response to an information signal and comprises analog drive circuits in a two-dimensional array of rows and columns, an analog sampling circuit that derives the analog samples from the information signal, and a sample distribution circuit. The sample distribution circuit receives the analog samples from the analog sampling circuit and distributes them to the analog drive circuits. The sample distribution circuit includes input gates corresponding to the analog drive circuits, column busses corresponding to the columns of the array, and a row selector having outputs corresponding to the rows of the array. The column busses distribute the analog samples column-wise to the analog drive circuits. The input gates connect the analog drive circuits to the column busses. Each output of the row selector is connected to control the input gates in one of the rows. The row selector sequentially opens the input gates in the rows to select the analog samples on the column busses row-wise.

Abstract: An integrated packaging system that comprises an integral mechanical support, a printed circuit board and the optical communications device. The mechanical support includes a first support element and a second support element. The first support element extends at a non-zero angle from the second support element. The printed circuit board includes a first portion and a second portion in contact with the first support element and the second support element, respectively. The optical communications device is mechanically coupled to the first support element of the mechanical support and is electrically connected to the first portion of the printed circuit board. The integrated packaging system preferably provides automatic alignment between the optical communications device and one or both of an optical element and an optical fiber. In this case, the first support element includes a device alignment feature.

Abstract: A flip-flop having a sleep mode in which power consumption is reduced. The flip-flop comprises a clock input, a data input, an input stage, an input gate, an output stage and an output clamp. The input gate is interposed between the data input and the input stage and operates in the sleep mode to isolate the input stage from the data input. The output stage is coupled to the input stage and includes an output having a first output state and a second output state. The output clamp operates in the sleep mode to set the output stage to a predetermined state regardless of the data states at the data input and the clock input. The predetermined state is the one of the output states in which the leakage power consumption of the flip-flop is less than in the other of the output states. The predetermined state may alternatively be the one of the output states in which the leakage power consumption of circuitry connected to the output of the flip-flop is less than in the other of the output states.

Abstract: An FBAR-based duplexer that comprises a first port, a second port, a third port, a first band-pass filter connected between the first port and the third port and a series circuit connected between the second port and the third port. The first band-pass filter includes a first ladder circuit having shunt and series elements. Each of the elements of the first ladder circuit comprises a film bulk acoustic resonator (FBAR). The series circuit includes a 90° phase shifter in series with a second band-pass filter. The second band-pass filter includes a second ladder circuit having shunt and series elements. Each of the elements of the second ladder circuit comprises a film bulk acoustic resonator. A band-pass filter comprising shunt elements and series elements in which the series elements and the shunt elements are connected to form a ladder circuit, and each of the elements includes a film bulk acoustic resonator (FBAR).

Abstract: The analog sampling circuit samples an analog input signal at intervals of time precisely defined by a master clock signal. The analog sampling circuit comprises N track-and-hold circuits and a clock signal generator. Each of the track-and-hold circuits includes a clock signal input. The clock signal generator includes a clock window signal generator and N gate circuits. The clock window signal generator comprises an input connected to receive the master clock signal, and N outputs, derives clock window signals from the master clock signal and feeds one of the clock window signals to each of the outputs. The clock window signals have imprecisely-timed edges. Each of the N gate circuits generates a sub-sampling clock signal with logic states defined by one of the clock window signals and with edge timings defined by the master clock signal independently of the imprecisely-timed edges of the clock window signal, and comprises a first input, a second input and an output.

Abstract: An electronic camera that can take pictures in which the subject desired by the photographer appears alone, in which the subject is emphasized relative to the background, and in which a desired hue characteristic of the subject can be emphasized or diminished without requiring the use of complex image processing performed by a computer. The effects of backlight are also eliminated or reduced, and the subject is correctly exposed under backlighting or dark background conditions. The electronic camera comprises a light source arranged to illuminate a subject, an image sensor having a reversible detection sense, a lens arranged to focus light from the subject on the image sensor, and a control system. The control system modulates the light source to generate amplitude-modulated light. The control system also reverses the detection sense of the image sensor in phase with the modulation of the amplitude-modulated light.

Abstract: A PCS that comprises a photo-conductive layer of NB material sandwiched between a top confinement layer and a bottom confinement layer. Both confinement layers are layers of WB material. NB material and WB material are semiconductor materials. NB material has a smaller band-gap energy than WB material. The top confinement layer and the photo-conductive layer have opposite conductivity types. A first electrode and a second electrode, separated from each other by a gap and are located on the surface of the top confinement layer remote from the photo-conductive layer. The photo-conductive layer provides a low-resistance conduction path between the electrodes when the photo-conductive layer is illuminated with incident light of an appropriate wavelength and intensity.

Abstract: The analog drive circuit drives a pixel electrode in response to an analog sample derived from a video signal. The analog drive circuit comprises a sample selection section and a drive signal generator. The sample selection section receives and temporarily stores the analog sample during a sample load period. The drive signal generator generates a drive signal and applies the drive signal to the pixel electrode during a display period that follows the sample load period. The drive signal is composed of a sequence of a first temporal portion and a second temporal portion. The first temporal portion has a time duration substantially proportional to the analog sample temporarily stored in the sample selection section. The second temporal portion is the temporal complement of the first temporal portion.

Abstract: A ferroelectric liquid crystal-based light valve comprising a light input, a light output, a polarizing beam splitter, a reflective spatial light modulator and a switchable half-wave plate. Light polarized parallel to a first direction is received through the light input. Light from the light input and reflected by the spatial light modulator is output from the light output. The reflective spatial light modulator is structured as a quarter-wave plate and has a principal axis that switches through an angle &phgr;. The polarizing beam splitter has orthogonal directions of maximum transmissivity and maximum reflectivity, one of which is parallel to the first direction.

Abstract: A p-contact that comprises a contact layer of a p-type Group III-nitride semiconductor having an exposed surface and an electrode layer of palladium (Pd) located on the exposed surface of the contact layer. The p-contact is made by providing a p-type Group III-nitride semiconductor contact layer having an exposed surface, and depositing an electrode layer of palladium on the exposed surface of the contact layer. Preferably, the p-contact is annealed for a prolonged annealing time after the electrode layer is deposited, and the exposed surface of the contact layer is etched using hydrofluoric acid (HF) before depositing the electrode layer.