Abstract: A variable optical attenuator (VOA) for use in an optical fiber communication system has a substrate, a thermal gradient prism and a heating element deposited on the prism. Heat is applied to the thermal gradient prism through the heating element. An optical signal is input into the prism via an optical signal input source. The optical signal traveling through the prism may be deflected due to a thermal gradient of the prism. The deflected optical signal is output into an optical signal output carrying medium. An optical signal strength measuring apparatus may measure a parameter related to the strength of the optical signal output into the optical signal output carrying medium.

Abstract: A laser apparatus and method that uses active thermalization of a reflective element to minimize losses and provide wavelength stability. The laser comprises first and second reflectors defining an external cavity, and a compensating member coupled to at least one of the reflectors and configured to thermally position one reflector with respect to the other reflector. The compensating member may be coupled directly to the first reflector and configured to position first reflector with respect to said second reflector. The thermal positioning may be carried out by a thermoelectric controller operatively coupled to the compensating member and configured to thermally adjust the compensating member by heating or cooling thereof. The laser apparatus may comprise a gain medium having first and second output facets and emitting a coherent beam from the first output facet along an optical path.

Abstract: A micromachined pellicle beam splitter and method of manufacture thereof are disclosed. In one embodiment, the beam splitter includes a silicon frame with a silicon nitride membrane attached to the frame and covering an opening through the frame. Other materials may be utilized, however, the coefficient of thermal expansion (CTE) of the membrane should be greater than that of the frame. The beam splitter may be manufactured by coating a silicon substrate with a layer of silicon nitride, patterning an opposite side of the silicon substrate with a photoresist or a metallic layer to define an opening an etching an opening through the substrate to the silicon nitride with either a dry etch or wet etch technique. An improved tunable laser module incorporating the micromachined pellicle beam splitter and a method of tuning a laser diode are also disclosed.

Abstract: A quasi-monochromatic light beam carrier for a particular telecommunication channel is likely to experience drift because of age, temperature, or other factors, and may cause the centroid wavelength of the carrier to shift. Temperature adjustments by wavelength lockers to compensate for drift on one channel may affect the performance of other channels. Embodiments of the present invention couple a quasi-monochromatic light beam through a substrate-based grating, diffract the light beam from the edge of the substrate to free space, and detect the light beam from free space at a position detector to determine the centroid wavelength based on a position of the light beam incident on the detector. The diffracted light beam may be reflected within the substrate a number of times prior to exiting the substrate towards the detector.

Abstract: A quasi-monochromatic light beam carrier for a particular telecommunication channel is likely to experience drift because of age, temperature, or other factors, and may cause the centroid wavelength of the carrier to shift. Temperature adjustments by wavelength lockers to compensate for drift on one channel may affect the performance of other channels. Embodiments of the present invention couple a quasi-monochromatic light beam through a substrate-based grating, diffract the light beam from the edge of the substrate to free space, and detect the light beam from free space at a position detector to determine the centroid wavelength based on a position of the light beam incident on the detector. The diffracted light beam may be reflected within the substrate a number of times prior to exiting the substrate towards the detector.

Abstract: A quasi-monochromatic light beam carrier for a particular telecommunication channel is likely to experience drift because of age, temperature, or other factors, and may cause the centroid wavelength of the carrier to shift. Temperature adjustments by wavelength lockers to compensate for drift on one channel may affect the performance of other channels. Embodiments of the present invention couple a quasi-monochromatic light beam through a substrate-based grating, diffract the light beam from the edge of the substrate to free space, and detect the light beam from free space at a position detector to determine the centroid wavelength based on a position of the light beam incident on the detector. The diffracted light beam may be reflected within the substrate a number of times prior to exiting the substrate towards the detector.

Abstract: A micromachined pellicle beam splitter and method of manufacture thereof are disclosed. In one embodiment, the beam splitter includes a silicon frame with a silicon nitride membrane attached to the frame and covering an opening through the frame. Other materials may be utilized, however, the coefficient of thermal expansion (CTE) of the membrane should be greater than that of the frame. The beam splitter may be manufactured by coating a silicon substrate with a layer of silicon nitride, patterning an opposite side of the silicon substrate with a photoresist or a metallic layer to define an opening an etching an opening through the substrate to the silicon nitride with either a dry etch or wet etch technique. An improved tunable laser module incorporating the micromachined pellicle beam splitter and a method of tuning a laser diode are also disclosed.

Abstract: A wireless display tag, adapted to fit within the C-channel of a shelf-edge, or otherwise usable as a hang tag or small identification device, includes, depending on implementation, an active transceiver, a passive transceiver, or both, with analog and digital control portions for managing communications with a host.

Abstract: A multiuse system for use with Wireless Display Tags (WDTs) includes, in one or more exemplary arrangements, techniques for automatically maintaining synchronicity between pricing data for a product and advertising, marketing or promotional data associated with that product, and for detecting the proximity and location of a customer within a category of goods displayed within a managed environment. A messaging format suitable for such low power operation among a large number of peers is also disclosed, as is a technique for integrating a plurality of smaller displays to yield a single large display. An access point capable of serving as a communications hub within such a network, while at the same time offering visual and audio surveillance capabilities, is also disclosed.

Abstract: Thermally tuned lasers may use a resistive thermal device (RTD), sensitive to hydrogen, within a hermetic enclosure. Over time, hydrogen trapped within the enclosure or out gassed from other components within the enclosure may degrade the accuracy of the RTD. A vent comprising a hydrogen selective permeable membrane, such as palladium or a palladium alloy, provided in the enclosure vents hydrogen to mitigate damage to the RTD.

Abstract: A method for error free initialization of a display tag includes providing a display tag, scanning the display tag with a near field source to cause the display tag to generate identification indicia, storing the identification indicia if only a single display tag generates that identification indicia, scanning the barcode of a product to be associated with the display tag, and associating, in a database, the identification indicia of the display tag with the barcode of the product to be associated with that display tag.

Abstract: A method for minimizing power consumption in a wireless device which utilizes backscatter transmission in half-duplex mode, wherein a switching device is interposed between an antenna and a transmitter-receiver, and the switching device is capable of causing the antenna load impedance characteristic to be either a short, a value which substantially matches the antenna impedance, or an open, depending on the portion of the half-duplex mode.

Abstract: A low-profile Wireless Display Tag (WDT) fits within the confines of a retail store display shelf-edge C-channel. The WDT may also be used to tag high-value retail item units where it can simultaneously function as a price tag, and an anti-theft device. The invention provides for bidirectional communication between the WDT and a central database. The invention uses a low profile antenna that may be painted onto a surface within the WDT. The WDT is capable of displaying graphics or variable format alphanumeric characters and the placement of display items is user programmable. The WDT uses an RF integrated Circuit (RFIC) that combines the backscatter RF communications method, amplified backscatter RF communications method and the active RF communications method.

Abstract: A low-power system for use with Wireless Display Tags (WDTs) includes, in one or more exemplary arrangements, various power management techniques, including receiver wake-up, RF logic sharing, RF repeaters and a frequency doubling power amplifier which operates on the absolute value of the input signal.

Abstract: A wavelength reference filter for receiving an input signal and producing a filtered output signal is provided. The operation of the filter is independent of the angle of incidence of the input signal. As a result, the output signal from the filter will maintain its wavelength, even under changes in the direction of propagation of the input signal to the filter. Without such incidence angle independence, a change to the input signal would change the output signal and result in inaccurate device operation. Example incidence angle independent filters may include a single etalon or multiple etalons. In the former example, a signal may traverse a single etalon twice, along paths that have different angular sensitivities relative to the etalon. In the latter example, each etalon may have an equal and opposite angular sensitivity, such that two the etalons have canceling angular sensitivities.

Abstract: A variable optical attenuator (VOA) for use in an optical fiber communication system has a substrate, a thermal gradient prism and a heating element deposited on the prism. Heat is applied to the thermal gradient prism through the heating element. An optical signal is input into the prism via an optical signal input source. The optical signal traveling through the prism may be deflected due to a thermal gradient of the prism. The deflected optical signal is output into an optical signal output carrying medium. An optical signal strength measuring apparatus may measure a parameter related to the strength of the optical signal output into the optical signal output carrying medium.

Abstract: A micromachined pellicle beam splitter and method of manufacture thereof are disclosed. In one embodiment, the beam splitter includes a silicon frame with a silicon nitride membrane attached to the frame and covering an opening through the frame. Other materials may be utilized, however, the coefficient of thermal expansion (CTE) of the membrane should be greater than that of the frame. The beam splitter may be manufactured by coating a silicon substrate with a layer of silicon nitride, patterning an opposite side of the silicon substrate with a photoresist or a metallic layer to define an opening an etching an opening through the substrate to the silicon nitride with either a dry etch or wet etch technique. An improved tunable laser module incorporating the micromachined pellicle beam splitter and a method of tuning a laser diode are also disclosed.

Abstract: A laser apparatus and method that uses active thermalization of a reflective element to minimize losses and provide wavelength stability. The laser comprises first and second reflectors defining an external cavity, and a compensating member coupled to at least one of the reflectors and configured to thermally position one reflector with respect to the other reflector. The compensating member may be coupled directly to the first reflector and configured to position first reflector with respect to said second reflector. The thermal positioning may be carried out by a thermoelectric controller operatively coupled to the compensating member and configured to thermally adjust the compensating member by heating or cooling thereof. The laser apparatus may comprise a gain medium having first and second output facets and emitting a coherent beam from the first output facet along an optical path.

Abstract: A micromachined pellicle beam splitter and method of manufacture thereof are disclosed. In one embodiment, the beam splitter includes a silicon frame with a silicon nitride membrane attached to the frame and covering an opening through the frame. Other materials may be utilized, however, the coefficient of thermal expansion (CTE) of the membrane should be greater than that of the frame. The beam splitter may be manufactured by coating a silicon substrate with a layer of silicon nitride, patterning an opposite side of the silicon substrate with a photoresist or a metallic layer to define an opening an etching an opening through the substrate to the silicon nitride with either a dry etch or wet etch technique. An improved tunable laser module incorporating the micromachined pellicle beam splitter and a method of tuning a laser diode are also disclosed.

Abstract: Anti-reflective coatings may be used on laser high index gain media to mitigate reflection. An absentee layer may be used to compliment the antireflective coating to improve its antireflective performance over a broader range of wavelengths. The absentee layer comprises a material having a higher index of refraction than that of the gain media and has a thickness corresponding to multiple halfwave thicknesses related to the center wavelength output by the laser.