Abstract: An HDMI interconnect arrangement is presented that performs a pulse-amplitude modulation (PAM) conversion of the TMDS audio/video signals in order to simultaneously transmit all three channels over a single optical fiber. The set of three audio/video TMDS channels is applied as an input to a PAM-8 optical modulator, which functions to encode the set of three channels onto an optically-modulated output signal. The modulated optical signal is thereafter coupled into an optical fiber within an active HDMI cable and transmitted to an HDMI receiver (sink). The TMDS CLK signal is not included in this conversion into the optical domain, but remains as a separate electrical signal to be transmitted along a copper signal path within the active HDMI cable.

Abstract: A silicon-based optical modulator is configured as a multi-segment device that utilizes a modified electrical data input signal format to address phase modulation nonlinearity and attenuation problems associated with free-carrier dispersion-based modulation. The modulator is formed to include M separate segments and a digital signal encoder is utilized to convert an N bit input data signal into a plurality of M drive signals for the M modulator segments, where M?2N/2. The lengths of the modulator segments may also be adjusted to address the nonlinearity and attenuation problems. Additional phase adjustments may be utilized at the output of the modulator (beyond the combining waveguide).

Abstract: An arrangement for collimating and turning an optical beam utilizing a pair of two-dimensional lenses to separate the collimation into separate one-dimensional operations, while using one of the two-dimensional lenses to also perform the turning operation. A first two-dimensional lensing surface is disposed at the endface of a launching waveguide. This first two-dimensional lensing surface provides collimation along one axis of the system (for example, the X axis). A second two-dimensional lensing surface is provided by introducing a defined curvature to a turning mirror in the system. The curvature of the turning mirror is designed to create collimation (or focusing, if desired) in the orthogonal beamfront (in this case, the Y axis beamfront), while also re-directing the propagating signal into the desired orientation.

Abstract: A system and method of providing on-line verification of various credentials without requiring second site authentication utilizes protocols and cryptography to assure customers (generally referred to hereinafter as “users”) that they are dealing with a person (or organization) that can present multiple, non-repudiable proof of their identification. The system is launched directly from the user's browser such that certificate verification is performed “locally”, without needing to go out and obtain information from a second web site. The system is based upon the creation of a new MIME (i.e. Multipurpose Internet Mail Extensions) type that is employed by the user's browser and utilizes public keys associated with the credentialing organizations in combination with a public key of the verification organization.

Abstract: An optical fiber coupler is formed of a section of optical fiber that is positioned between a conventional input fiber (for example, a single mode fiber) or waveguide and a coiled optical fiber device. The adiabatic coupler is coiled (or, at least, curved) to assist in transforming a conventional fundamental mode optical signal propagating along the longitudinal axis of the input fiber to an optical signal that is shifted into a peripheral region of the coiled optical fiber. Moreover, the pitch of an inventive coiled optical fiber coupler can be controlled to assist in the adiabatic transformation process.

Abstract: A hydrogen-resistant optical fiber particularly well-suitable for downhole applications comprises a relatively thick pure silica core and a depressed-index cladding layer. Interposed between the depressed-index cladding layer and the core is a relatively thin germanium-doped interface. By maintaining a proper relationship between the pure silica core diameter and the thickness of the germanium-doped interface, a majority (preferably, more than 65%) of the propagating signal can be confined within the pure silica core and, therefore, be protected from hydrogen-induced attenuation problems associated with the presence of germanium (as is common in downhole fiber applications). The hydrogen-resistant fiber of the present invention can be formed to include one or more Bragg gratings within the germanium-doped interface, useful for sensing applications.

Abstract: An isothermal, low pressure-based process of depositing material within a substrate has been developed, and is particularly useful in forming an optical fiber preform results in creating an extremely narrow reaction zone within which a more uniform and efficient deposition will occur. Sets of isothermal plasma operating conditions have been found that create a narrow deposition zone, assuring that the deposited material is clear glass rather than soot particles. The exhaust end of the tube is connected to a vacuum system which is in turn connected to a scrubber apparatus for removal and neutralization of reaction by-products. The operating conditions are selected such that the hot plasma does not transfer a substantial amount of heat to the substrate tube, where the presence of such heat has been found to result in vaporizing the reactant material (creating soot) and developing hot spots.

Abstract: A rotating perforation apparatus contains a plurality of needle points (or other piercing features) formed along a free-wheeling support bar, where the bar is positioned to contact the film while it is being unrolled and is in a ‘tensioned’ state (in some embodiments, immediately prior to contacting the element to be wrapped). In particular, the free-wheeling perforation apparatus contacts a mechanized film roller such that the exposed needle points will rotate against the mechanized roller and make the perforations in the film as it travels over the film roller. As long as the film roller is formed of a pliable material, the needles will pierce the film and create the desired perforations. The size and placement of needles can be adjusted to provide the required pattern of perforations, as well as dictate the size of the actual perforations.

Abstract: A mode filter for eliminating the propagation of higher-order modes along a section of optical multimode fiber comprises a graded index (GRIN) lens, preferably of a quarter-pitch length, and a pinhole element in the form of a small core fiber. This configuration creates a Fourier spatial filter assembly that removes higher order modes propagating along an optical fiber while capturing the fundamental mode of the optical signal. A section of GRIN fiber is preferably used as the lens, with the small core fiber disposed at the output of the GRIN fiber lens to collect substantially only the on-axis fundamental mode of the optical signal. Since the higher order modes are shifted away from the origin by the GRIN fiber lens, only the fundamental mode signal is captured by the small core fiber.

Abstract: A multiple piecepart alignment and attachment configuration for mating a fiber array (or even a single fiber) with a silicon photonic subassembly utilizes ever-tightening alignment tolerances to align the fiber array with a similar array of waveguides (or other devices) formed within the photonic subassembly. A box-shaped fiber holder is formed to include a plurality of grooves within its bottom interior surface to initially support the fiber array. A separate piecepart in the form of a lid is mated to, and aligned with, the silicon photonic subassembly. The lid is formed to include registration features on its underside that fit into alignment detents formed in the top surface of the silicon photonic subassembly upon attachment. The lid also includes a number of grooves formed on its underside that will capture the top surface of the fibers as the fiber holder is slide into place over the lid.

Abstract: An apparatus and method for producing optical pulses of a desired wavelength utilizes a section of higher-order-mode (HOM) fiber to receive input optical pulses at a first wavelength, and thereafter produce output optical pulses at the desired wavelength through soliton self-frequency shifting (SSFS) or Cherenkov radiation. The HOM fiber is configured to exhibit a large positive dispersion and effective area at wavelengths less than 1300 nm.

Abstract: A plasma-based etching process is used to specifically shape the endface of an optical substrate supporting an optical waveguide into a contoured facet which will improve coupling efficiency between the waveguide and a free space optical signal. The ability to use standard photolithographic techniques to pattern and etch the optical endface facet allows for virtually any desired facet geometry to be formed—and replicated across the surface of a wafer for the entire group of assemblies being fabricated. A lens may be etched into the endface using a properly-defined photolithographic mask, with the focal point of the lens selected with respect to the parameters of the optical waveguide and the propagating free space signal. Alternatively, an angled facet may be formed along the endface, with the angle sufficient to re-direct reflected/scattered signals away from the optical axis.

Abstract: An optical delay line is formed from a coil of optical fiber (in many cases microfiber), where the radius of the optical fiber is greater than the wavelength ? of the propagating signal and the radius R of the coil is selected, in consideration with the optical fiber radius, to limit propagation loss by minimizing coupling between adjacent turns of the coil. The difference in dimension between the fiber diameter and wavelength prevents the mode propagating along one turn from coupling into an adjacent turn. It has been discovered that the modal intensity at the interface between the central rod and the coil will be minimized when the radius of the fiber satisfies the following condition: r >> ( R ? 2 ) 1 / 3 , where ?=(2?n)/?, and n is the refractive index of the fiber.

Abstract: An optical coupler is formed of a low index material and exhibits a mode field diameter suitable to provide efficient coupling between a free space optical signal (of large mode field diameter) and a single mode high index waveguide formed on an optical substrate. One embodiment comprises an antiresonant reflecting optical waveguide (ARROW) structure in conjunction with an embedded (high index) nanotaper coupling waveguide. Another embodiment utilizes a low index waveguide structure disposed in an overlapped arrangement with a high index nanotaper coupling waveguide. The low index waveguide itself includes a tapered region that overlies the nanotaper coupling waveguide to facilitate the transfer of the optical energy from the low index waveguide into an associated single mode high index waveguide. Methods of forming these devices using CMOS processes are also disclosed.

Abstract: A method and apparatus for conditioning polishing pads that utilizes an apertured conditioning disk for introducing operation-specific slurries, without the need for additional tooling, platens, and materials handling. The method and apparatus utilizes a vacuum capability to pull waste material out of the polishing pad and through the apertured conditioning disk to evacuate the apparatus through an outlet port. The apparatus also includes a force adjustment system for providing measurement and control of the force applied by the conditioning disk to the polishing pad.

Abstract: In accordance with the present invention, a bulk optic material (for example, silica) is processed to form a spatially microstructured element, such as a photonic bandgap (PBG) structure. An ultra-short laser pulse source is used as an input signal that is applied to the bulk optic PBG structure to generate an enhanced continuum output. The PBG structure may comprise any type of one-, two- or three-dimensional grating structure, where the selected structure will dictate the type(s) of enhancement(s) that are present in the generated continuum—generally in the form of a broadened continuum and/or the inclusion of one or peaks in the continuum. The use of a relatively small-dimensioned bulk material allows for the continuum to be generated without the need for any type of optical confinement (waveguide). In one embodiment, the bulk PBG structure may be is subjected to one or more additional processes (such as UV exposure, electromagnetic field application, etc.

Abstract: An apparatus for cutting a pipe includes a housing with a central aperture for holding the pipe in a fixed position. A rotatable collar is mounted on the outer surface of the fixed housing, with a cutting head attached to the collar. The cutting head is configured to translate forward and backward such that the combination of the rotational movement of the collar and the translational movement of the cutting head is capable of performing complex cuts without ever moving the pipe. A number of different cutting tools (laser, plasma, etc.) may be attached to the cutting head, and a variety of different tasks may be performed including cutting completely through the entire pipe, inscribing on the pipe surface, forming through-holes along the pipe, and the like.

Abstract: A low loss optical waveguiding structure for silicon-on-insulator (SOI)-based arrangements utilizes a tri-material configuration including a rib/strip waveguide formed of a material with a refractive index less than silicon, but greater than the refractive index of the underlying insulating material. In one arrangement, silicon nitride may be used. The index mismatch between the silicon surface layer (the SOI layer) and the rib/strip waveguide results in a majority of the optical energy remaining within the SOI layer, thus reducing scattering losses from the rib/strip structure (while the rib/strip allows for guiding along a desired signal path to be followed). Further, since silicon nitride is an amorphous material without a grain structure, this will also reduce scattering losses. Advantageously, the use of silicon nitride allows for conventional CMOS fabrication processes to be used in forming both passive and active devices.

Abstract: A polarization-maintaining figure eight (PMFE) fiber laser is configured to generate ultrashort (femtosecond) output pulses by intentionally inserting asymmetry (in the form of a phase bias) into the bi-directional loop of the fiber laser. The introduction of asymmetry (via an asymmetric coupler, splice, attenuator, fiber bend, multiple amplifying sections, or the like) allows for an accumulation of phase difference within the bi-directional loop sufficient to create modelocking and generate ultrashort output pulses.

Abstract: A compact, integrated LIDAR system utilizes SOI-based opto-electronic components to provide for lower cost and higher reliability as compared to current LIDAR systems. Preferably, an SOI-based LIDAR transmitter and an SOI-based LIDAR receiver (both optical components and electrical components) are integrated within a single module. The various optical and electrical components are formed utilizing portions of the SOI layer and applying well-known CMOS fabrication processes (e.g., patterning, etching, doping), including the formation of additional layer(s) over the SOI layer to provide the required devices. A laser source itself is attached to the SOI arrangement and coupled through an integrated modulation device (such as a Mach-Zehnder interferometer, i.e., MZI) to provide the scanning laser output signal (the scan controlled by, for example, an electrical (encoder) input to the input to the MZI).