Abstract: In an optical modulator directional measurement system embodiment, one or more modulation waves may be measured and directionally discriminated by measuring the modulations of one or more lightwaves. The optical modulator transmission function magnitude for a most phase-matched modulation may be substantially greater than that for other modulations. At sufficiently high modulation frequency, the most phase-matched modulation magnitude may be substantially greater than the other modulation magnitudes. Accordingly, a modulation wave may be distinctly measured by measuring the modulation of the most phase-matched lightwave.

Abstract: In an optical modulator directional measurement system embodiment, one or more modulation waves may be measured and directionally discriminated by measuring the modulations of one or more lightwaves. The optical modulator transmission function magnitude for a most phase-matched modulation may be substantially greater than that for other modulations. At sufficiently high modulation frequency, the most phase-matched modulation magnitude may be substantially greater than the other modulation magnitudes. Accordingly, a modulation wave may be distinctly measured by measuring the modulation of the most phase-matched lightwave.

Abstract: In an optical modulator directional measurement system embodiment, one or more modulation waves may be measured and directionally discriminated by measuring the modulations of one or more lightwaves. The optical modulator transmission function magnitude for a most phase-matched modulation may be substantially greater than that for other modulations. At sufficiently high modulation frequency, the most phase-matched modulation magnitude may be substantially greater than the other modulation magnitudes. Accordingly, a modulation wave may be distinctly measured by measuring the modulation of the most phase-matched lightwave.

Abstract: In a gap-mode waveguide embodiment, an interior gap in a tubular waveguide principally condenses a dominant gap mode near the interior gap, and an absorber dissipates electromagnetic energy away from the gap mode. In this manner, the gap mode may dissipate relatively little power in the absorber compared to other modes and propagate with lesser attenuation than all other modes. A gap mode launched into a gap-mode waveguide may provide for low-loss, low-dispersion propagation of signals over a bandwidth including a multimode range of the waveguide. Gap-mode waveguide embodiments of various forms may be used to build guided-wave circuits covering broad bandwidths extending to terahertz frequencies.

Abstract: In an optical modulator directional measurement system embodiment, one or more modulation waves may be measured and directionally discriminated by measuring the modulations of one or more lightwaves. The optical modulator transmission function magnitude for a most phase-matched modulation may be substantially greater than that for other modulations. At sufficiently high modulation frequency, the most phase-matched modulation magnitude may be substantially greater than the other modulation magnitudes. Accordingly, a modulation wave may be distinctly measured by measuring the modulation of the most phase-matched lightwave.

Abstract: In a gap-mode waveguide embodiment, an interior gap in a tubular waveguide principally condenses a dominant gap mode near the interior gap, and an absorber dissipates electromagnetic energy away from the gap mode. In this manner, the gap mode may dissipate relatively little power in the absorber compared to other modes and propagate with lesser attenuation than all other modes. A gap mode launched into a gap-mode waveguide may provide for low-loss, low-dispersion propagation of signals over a bandwidth including a multimode range of the waveguide. Gap-mode waveguide embodiments of various forms may be used to build guided-wave circuits covering broad bandwidths extending to terahertz frequencies.

Abstract: A shielded high-frequency circuit module includes a conductive frame electrically coupled to a top surface of a printed circuit board and a lid. The conductive frame includes inner walls, which define a circuit region, at least a portion of which includes a circuit on the top surface of the printed circuit board. The shielded high-frequency circuit module also includes a connector for interfacing the circuit region with high-frequency signals outside the conductive frame, at least a portion of the connector being electrically coupled to the conductive frame. The inner walls of the conductive frame, the top surface of the printed circuit board and the lid define a shield surrounding the circuit region.

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 shield for an electronic circuit for controlling electromagnetic radiation. The circuit is constructed on a PCB having a minimum of three metal layers. The PCB includes SMT shield connectors for carrying signals to the circuit. The shield includes a metal wall portion mounted to the PCB and a removable metal lid mounted to the wall portion. The PCB, connectors, wall portion and lid together form a continuous electromagnetic barrier around the circuit.

Abstract: A frequency modulated (FM) vertical cavity surface emitting laser (VCSEL). The frequency modulated VCSEL includes a mirror region that has an active region. The frequency modulated VCSEL also includes a phase adjustment region for use in altering the characteristics of the VCSEL. For example, by changing the index of refraction in the phase adjustment region, the wavelength of the VCSEL can be changed, resulting in frequency modulation.

Abstract: An enclosure for an optical communications device having a lid portion and a base portion. Alignment members adapted to interface with an optical connector are formed on the lid portion. The lid portion is affixed to the base portion with a portion of the communications components therebetween. Multiple base portions formed in a unitary piece of material and multiple lid portions formed in another unitary piece of material can be affixed to one another, and then separated into individual devices to minimize time spent aligning each base and lid portion.

Abstract: An electrical interconnection includes a flex-circuit having a signal conductor and a shield conductor. A mating surface of the flex-circuit has a signal conductor portion surrounded by a shield conductor portion. The signal conductor portion is electrically coupled to the signal conductor and the shield conductor portion is electrically coupled to the shield conductor.

Abstract: The packaging system comprises a mechanical support, an insulating substrate and an electronic circuit. The mechanical support has a first support element that extends at a non-zero angle from a second support element. The insulating substrate has a first portion and a second portion in contact with the first support element and the second support element, respectively. The first portion is contoured to define at least one access hole. The optical communications device and the electronic circuit are mechanically coupled to the first support element. Either or both the optical communications device and the electronic circuit is mechanically coupled to the first support element through a respective one of the at least one access hole. The packaging device additionally comprises a conductive track extending between the electronic circuit and the optical communications device on the first portion of the insulating substrate.

Abstract: A unipolar photodiode and methods of making and using employ a Schottky contact as a cathode contact. The Schottky cathode contact is created directly on a carrier traveling or collector layer of the unipolar photodiode resulting in a simpler overall structure to use and make. The unipolar photodiode comprises a light absorption layer, the collector layer adjacent to the light absorption layer, the Schottky cathode contact in direct contact with the collector layer, and an anode contact either directly or indirectly interfaced to the light absorption layer. The light absorption layer has a doping concentration that is greater than a doping concentration of the collector layer. The light absorption layer has a band gap energy that is less than that of the collector layer. The light absorption layer and the collector layer may be of the same or opposite conduction type.

Abstract: A symmetrical photo-amplifier circuit with improved power supply rejection includes a signal circuit and a reference circuit, in which the electrical capacitances and parasitic capacitances from mechanical sources, such as bond wires and substrates, are matched between the signal circuit and the reference circuit.

Abstract: A frequency modulated (FM) vertical cavity surface emitting laser (VCSEL). The frequency modulated VCSEL includes a mirror region that has an active region. The frequency modulated VCSEL also includes a phase adjustment region for use in altering the characteristics of the VCSEL. For example, by changing the index of refraction in the phase adjustment region, the wavelength of the VCSEL can be changed, resulting in frequency modulation.

Abstract: A unipolar photodiode and methods of making and using employ a Schottky contact as a cathode contact. The Schottky cathode contact is created directly on a carrier traveling or collector layer of the unipolar photodiode resulting in a simpler overall structure to use and make. The unipolar photodiode comprises a light absorption layer, the collector layer adjacent to the light absorption layer, the Schottky cathode contact in direct contact with the collector layer, and an anode contact either directly or indirectly interfaced to the light absorption layer. The light absorption layer has a doping concentration that is greater than a doping concentration of the collector layer. The light absorption layer has a band gap energy that is less than that of the collector layer. The light absorption layer and the collector layer may be of the same or opposite conduction type.

Abstract: An apparatus for coupling light from a light source into an optical waveguide having an entrance aperture for receiving light to be transmitted by the waveguide. The entrance aperture has a numerical aperture that may vary over the aperture. The apparatus includes an optical element that conditions the light from the light source and a diffractive optical element. The diffractive optical element generates a plurality of light spots from the light source. The light from each light spot enters the entrance aperture of the waveguide at a different point on the entrance aperture. Each of the light spots has a numerical aperture that is less than the numerical aperture of the entrance aperture at the point on the entrance aperture at which the light from that light spots enters the entrance aperture.

Abstract: An enhanced extended drift heterostructure (EEDH) photodiode and method of making provide enhanced electron response. The EEDH photodiode includes adjacent first and second light absorption layers, an ohmic anode contact interfaced to the first layer and a cathode contact interfaced to the second layer. The cathode contact includes either a Schottky cathode contact or an ohmic cathode contact and a contact layer. The EEDH photodiode optionally further includes one or more of a carrier block layer interfaced to the first layer, a graded characteristic in the first layer, and a collector layer interfaced to the second layer. The first layer has a doping concentration that is greater than doping concentrations of the second layer and the optional collector layer. The first and second layers have band gap energies that facilitate light absorption. The optional layers have band gap energies that are relatively nonconducive to light absorption.

Abstract: A method is disclosed by which precision alignment of optical fiber to wave-guide or other optical elements can be carried out with an adjustable microstructure in active alignment mode fiber attachment. A microstructure containing three elongated U-grooves can be combined effectively to produce a movable and adjustable V-groove structure, which can be used to achieve sub-micron scale alignment control with zero rotational torque. This device not only makes fiber alignment easy and fast but also maintains the fiber attachment position after alignment and epoxy bonding. Multiple fiber array alignment can be carried out with only a global alignment of two end fibers.