Abstract: A method and apparatus is provided for attaching a bulk element processing an optical beam to a PLC and optically aligning the bulk element with an optical element formed on the PLC. The method begins by securing the bulk element to a first side of a substrate. A first side of a flexure element is secured to the first side of the substrate. A second side of the flexure element is secured to a first side of the PLC on which the optical element is formed such that the bulk element and the optical element are in optical alignment to within a first level of tolerance. Subsequent to the step of securing the second side of the flexure element, a force is exerted on at least a second side of the substrate to thereby flex the flexure element. The force causes sufficient flexure of the flexure element to optically align the bulk element and optical element to within a second level of tolerance that is more stringent than the first level of tolerance.

Abstract: A fiber-optic-taper loop probe includes first and second fiber segments, first and second tapering segments, and a center taper segment. In a preferred embodiment, first and second fiber segments are about 125 ?m in diameter, and the center taper segment has a substantially constant diameter of about 2-5 ?m. The fiber-optic taper forms a loop, the center taper segment remaining substantially straight and opposite the crossing point of the loop. The loop is secured to a support structure to maintain its shape and facilitate positioning relative to an optical component to be tested. The fiber segments may be connected to an optical characterization system including one or more light sources, lasers, detectors, spectrometers, etc. The geometry of the loop enables transverse-optical-coupling of the loop probe with an optical component without undesirable contact between other portions of the loop probe and other portions of the optical component and/or substrate.

Abstract: A short laser cavity (up to 30 cm in length) comprising a free-space tunable MEMS Fabry-Perot filter, a collimating lens and a section of erbium-doped phosphate gain fiber (2-25 cm) is formed between a pair of broadband reflectors. The cavity is optically pumped to excite the erbium ions and provide gain, which establishes an initial longitudinal mode structure that spans the C-band with a mode spacing of at least 0.3 GHz and a roundtrip unsaturated gain of at least 8 dB over the tuning range. A controller tunes the MEMS filter, which has a filter function whose spectral width is at most ten and preferably less than four times the longitudinal mode spacing, to align its transmission maxima to one of a plurality of discrete output wavelengths that span the C-band. A thermal control element adjusts the longitudinal mode structure to align a single mode with the transmission maxima of the filter.

Abstract: The present disclosure is directed to laser apparatuses for generating coherent electromagnetic laser radiation having an electron beam generator, a diffraction grating element oriented such that a beam of electrons from the electron beam generator is directed over the diffraction grating element, and at least one wing element coupled to the diffraction grating element. In some embodiments, the wing element(s) can be coupled to a top portion of the diffraction grating element. While in others, the wing element(s) can be coupled to a side portion of the diffraction grating element. The present disclosure is also directed to methods of manufacturing diffraction grating elements involving placing at least one secondary conducting sheet having a first height on at least one primary conductive sheet having a different second height, and securing the primary and secondary conductive sheets together. The primary and secondary conductive sheets can be alternating and their thicknesses may also be different.

Abstract: Methods, systems, devices and the like for measuring, encoding and displaying of object color for digital imaging, to control the apparent color of an item under different lighting or display conditions. The present invention helps provide accurate color for such items, both on the internet and in other situations, and can, if desired, determine whether a display screen is accurately displaying the color and also correct the image on the screen if it is not accurate. Also, probes suitable for taking accurate measurements of the intrinsic color characteristics, or intrinsic wavelength-dependent response, of an object, and software or databases that provide information for a variety of lighting situations and light sources.

Abstract: An optical module is provided for performing a prescribed function such as dispersion compensation, for example. The optical module is to be integrated between stages of a multi-stage rare-earth doped optical amplifier. The module includes an input port for receiving optical energy from one stage of the rare-earth doped optical amplifier and a rare-earth doped planar waveguide coupled to the input port. An optically lossy, passive element is provided for performing the prescribed function. The optically lossy, passive element is coupled to the planar waveguide for receiving optical energy therefrom. An output port is coupled to the optically lossy, passive element for providing optical energy to another stage of the rare-earth doped optical amplifier.

Abstract: A multi-layer laterally-confined dispersion-engineered optical waveguide may include one multi-layer reflector stack for guiding an optical mode along a surface thereof, or may include two multi-layer reflector stacks with a core therebetween for guiding an optical mode along the core. Dispersive properties of such multi-layer waveguides enable modal-index-matching between low-index optical fibers and/or waveguides and high-index integrated optical components and efficient transfer of optical signal power therebetween. Integrated optical devices incorporating such multi-layer waveguides may therefore exhibit low (<3 dB) insertion losses. Incorporation of an active layer (electro-optic, electro-absorptive, non-linear-optical) into such waveguides enables active control of optical loss and/or modal index with relatively low-voltage/low-intensity control signals. Integrated optical devices incorporating such waveguides may therefore exhibit relatively low drive signal requirements.

Abstract: The present invention relates to a single-chip light-emitting diode (LED) with three luminescent spectrums of red, blue and green wavelengths. The single-chip light-emitting diode of the invention comprises a base, two conductive pins, a single-chip light-emitting element, a package material, and red fluorescent powder. The single-chip light-emitting element is disposed on the base and electrically connected to the two conductive pins. The red fluorescent powder is added to the package material. The single-chip light-emitting element comprises a substrate, an N-type cladding layer, a P-type cladding layer, at least one green light-emitting layer, and at least one blue light-emitting layer. The green light-emitting and blue light-emitting layers are formed between the N-type cladding layer and the P-type cladding layer.

Abstract: A fiber Bragg grating compression sensor and a flexure mount that is attached to the sensor to significantly enhance its compression sensitivity. By incorporating the flexure mount, compressive forces are converted to tensile forces allowing an entire new set of measurement possibilities. The sensor may be used in implantable tendon and ligament force sensing or as a generalized compression sensor.

Abstract: An ultrasonic probe comprising a piezoelectric element, a first electrode formed on a substantial portion of a first main face, a first side face and a part of a second main face of the piezoelectric element, and a second electrode formed on a substantial portion of a second main face, a second side face and a part of a first main face of the piezoelectric element, the two electrodes being isolated from each other by two grooves formed on the first and second main faces of the piezoelectric element, in a manner parallel to the side edges of the piezoelectric element, respectively, has good vibration and probing properties.

Abstract: In one embodiment, a method of forming a multijunction solar cell having lattice mismatched layers and lattice-matched layers comprises growing a top subcell having a first band gap over a growth semiconductor substrate. A middle subcell having a second band gap is grown over the top subcell, and a lower subcell having a third band gap is grown over the middle subcell. The lower subcell is substantially lattice-mismatched with respect to the growth semiconductor substrate. The first band gap of the top subcell is larger than the second band gap of the middle subcell. The second band gap of the middle subcell is larger than the third band gap of the lower subcell. A support substrate is formed over the lower subcell, and the growth semiconductor substrate is removed. In various embodiments, the multijunction solar cell may further comprise additional lower subcells. A parting layer may also be provided between the growth substrate and the top subcell in certain embodiments.

Abstract: A mode coupling device is provided for coupling co-propagating modes in an optical waveguide to provide a gain flattening filter for use with an optical amplifier such as an erbium-doped fiber amplifier. The mode coupling device includes a plurality of long period grating sections having equal spatial periods, with adjacent grating sections separated by an interval of less than 10 periods in length. Also provided is a method for manufacturing the mode coupling device, including a method for determining the parameters of the device and a method for fine tuning the device to provide a loss spectrum closely matching the output spectrum of the optical amplifier. The mode coupling device is useful for flattening the gain of the optical amplifier.

Abstract: The invention consists of a system and method for regenerating and converting optical signals. The invention provides both “2R (i.e. reamplification and reshaping) and “3R” (i.e. reamplification, reshaping, and resynchronization (or retiming)) regeneration. The components of the inventive system include a tunable continuous wave (CW) laser source, an optical circulator, an semiconductor optical amplifier (SOA), and a spectral filter that has a very sharp cutoff frequency. In alternative embodiments, the filter may be replaced with an interleaver that passes several wavelengths. A single interleaver may be used by several of the optical regenerators/converters described herein. Each regenerator uses a separate wavelength that is associated with a passband frequency of the single interleaver. During counter-propagation in the SOA, a CW signal from the CW laser is chirped by bits in an input signal. The chirped signal is then output to the filter, which blocks the original CW signal.

Abstract: A packaged fiber-coupled optical device comprises an alignment housing with a fiber retainer, optical fiber segment(s), and optical component(s) (on substrate(s) with fiber groove(s)). Upon assembly the protruding end(s) of the fiber segment(s) is/are positioned against the fiber retainer, and the fiber groove(s) is/are aligned with the protruding end(s) of the fiber segment(s). The fiber retainer urges the protruding end(s) of the fiber segment(s) into the fiber groove(s). The fiber groove(s) position the protruding end(s) of the optical fiber(s) seated therein for optical coupling with optical component(s). The alignment housing and/or a fiber subassembly may be configured for engaging a mating fiber-optic connector.

Abstract: A narrow-linewidth high-power single-frequency laser is realized by pumping a laser cavity with a pair of polarized single-mode pump lasers that are driven below their respective “micro-kink” regions and combined with a polarized beam combiner. The pump lasers emit at the same wavelength and include a length of polarization-maintaining (PM) fiber to maintain the polarization of the respective pumps. The laser cavity is selected from microchip, fiber and waveguide devices and is provided with optical feedback. This laser is capable of producing a stable high-power single-mode signal with a very narrow linewidth, e.g. less than 10 kHz and preferably less than 3 kHz.

Abstract: An optical device (300) including first and second facets (340, 350); an at least partially bent waveguide (320) formed on a substrate and including a portion perpendicular to the first facet; and a light amplification region (310) coupled to the bent waveguide. The light amplification region includes an expanding tapered portion and a contracting tapered portion which approaches the second facet.

Abstract: The invention relates to a line for processing an optical fiber having first and second ends, the line comprising a support for receiving a reel with the fiber wounded thereon; a de-winder for unwinding the fiber without substantial rotation of the reel; and a processing station for receiving the optical fiber from said de-winder to perform a processing on a portion of the optical fiber. The invention also relates to a method for writing a grating on a fiber having first and second ends, the fiber being wounded on a first reel and being capable of being wounded on a second reel, the method comprising connecting the first end of the fiber to a circulator; connecting said circulator to a source of light and to a first measurement means; de-winding the fiber from the first reel without rotation of the reel; writing a grating on the fiber with a source of radiation; and measuring reflection spectra of the grating with said first measurement means.

Abstract: A waveguide device is provided comprising an optical waveguide core and a cladding optically coupled to the optical waveguide core. The cladding comprises an optically functional region defining a refractive index that is configured to vary in response to a control signal applied to the optically functional region. The refractive index of the optically functional region is lower than the refractive index of the optical waveguide core. In accordance with one embodiment of the present invention, the optically functional region may be characterized as a Kerr Effect medium.

Abstract: A semiconductor laser diode and method are described, wherein the path of the current through the device between the positive and negative conductors is controlled. Lateral spread of the gain current in the active region is prevented by implanting protons in areas of the active layer flanking a desired gain region. The implanted regions become less conductive, and prevent lateral spread of the gain current. The position of the implanted regions can be selected so that the gain current only crosses a portion of the active layer that supports desired lateral modes of the laser light.

Abstract: A long period chiral fiber grating (“LPCFG”) that has a number of advantageous properties that can be readily utilized in a number of different applications is provided. The inventive LPCFG is a fiber grating having a pitch that exceeds the wavelength of light propagating therethrough. The LPCFG includes a number of dips in its transmission spectrum, but does not reflect any portion of the signal passing therethrough. The LPCFG is sensitive to changes in the refractive index of its external environment (or in the refractive index of a coating covering the LPCFG cladding). In response to changes in the external refractive index, the transmission dips shift proportionally to changes in the index, thus enabling the use of LPCFG as a fiber sensor element. In addition, the LPCFG is polarization sensitive—one circular polarized wave of one handedness is coupled to the cladding mode stronger than the wave of the other polarization handedness.