Abstract: Present thermal solutions to conduct heat from pluggable optical modules into heat sinks use a metal heat sink attached with a spring clip. The interface between the pluggable module and the heat sink is simple metal-on-metal contact, which is inherently a poor thermal interface and limits heat dissipation from the optical module. Heat dissipation from pluggable optical modules is enhanced by the application of thermally conductive fibers, such as an advanced carbon nanotube velvet. The solution improves heat dissipation while preserving the removable nature of the optical modules.

Abstract: A package for an arcuate planar lightwave circuit (PLC) chip includes a heater plate coupled to a base by a thick and soft support layer. The arcuate PLC is attached to the heater plate by soft adhesive. A hard adhesive is applied to a multi-waveguide end of the arcuate PLC, to additionally strengthen the attachment of the arcuate PLC to the heater plate. The structure allows the mechanical stress due to fiber pull/shock/vibration to be dissipated in the support layer without introducing large wavelength shifts in the arcuate PLC. The support layer also serves as a heat insulator, facilitating uniform heating of the arcuate PLC.

Abstract: A wavelength selection switch (1) equipped with: an input/output unit (10) having multiple input/output ports that input/output signal light; a light-collecting mirror (14) arranged in the light path of the signal light from the input/output unit; a dispersion element (13) having a dispersion part and a non-dispersion part that does not have a dispersion effect; and multiple deflection elements (16) arranged in the direction in which the signal light is dispersed. The light-collecting mirror (14) causes the signal light from the input/output unit (10) to enter the dispersion part of the dispersion element (13), and the light that is dispersed by the dispersion element (13) is collected in the deflection elements (16) through the non-dispersion part of the dispersion element (13). Furthermore, the deflection elements (16) deflect the collected light such that the light is emitted from a prescribed input/output port of the multiple input/output ports.

Abstract: Fiber burning and/or overheating of the fiber feedthrough in high-power laser modules, which may cause catastrophic and/or collateral damage, may be addressed by providing an optical fiber assembly designed to withstand overheating due to errant high power laser light that is directed toward the input core of a fiber but may be at least partially misaligned. The optical fiber may be secured within a mount having a passageway such that the end face of the optical fiber extends past an opening of the passageway to a focal plane of the incident light. The end of the optical fiber may include a section that has a reduced or absent cladding layer (e.g., etched to form a tapered cladding region) so as to reduce the amount of light captured by the cladding and/or to leak the light out quickly.

Abstract: A time of flight camera device comprises an light source for illuminating an environment including an object with light of a first wavelength; an image sensor for measuring time the light has taken to travel from the light source to the object and back; optics for gathering reflected light from the object and imaging the environment onto the image sensor; driver electronics for controlling the light source with a high speed signal at a clock frequency; and a controller for calculating the distance between the object and the illumination unit. To minimize power consumption and resulting heat dissipation requirements, the light source/driver electronics are operated at their resonant frequency. Ideally, the driver electronics includes a reactance adjuster for changing a resonant frequency of the illumination unit and driver electronics system.

Abstract: The invention provides a tunable coherent optical receiver and a related method wherein the receiver uses low-frequency trace-tone modulation of optical WDM channels at transmission as channel IDs in order to detect which optical channels are present in the received optical WDM signal. The receiver than discriminates between the thereby detected optical channels by tuning a local oscillator to one of the received optical channels as determined based on the presence of the low-frequency tones in the received optical signal.

Abstract: An opto-electronic package having two enclosures in which a first non-hermetic enclosure provides the structural rigidity required to maintain the alignment of the optical components for a predetermined environmental range, and second flexible enclosure that provides a hermetical seal for the opto-electronic package.

Abstract: Direct pin attachment is the most compact method to connect the OSA and the PCBA, due to better performance in general and allows maximum PCBA space for more functionality. However, direct pin attachment can result in concentrated stress in the OSA-PCBA joint area, which can affect the reliability and yield of the module. To overcome the problem, an integrated transceiver cage and housing is provided including a direct pin attachment with reinforcing tabs, which are fixed to the PCBA prior to the pins to transfer any stress between the OSA and PCBA, thereby reducing the amount of stress applied to the pins.

Abstract: A modal instability of a fiber amplifier may be reduced by coupling, e.g. splicing, a length of passive multimode optical fiber to an active multimode optical fiber of the fiber amplifier. Upon launching light into the passive optical fiber, some higher order transversal modes may be excited in the passive optical fiber. The higher-order modes may interfere with the fundamental mode in the passive multimode optical fiber. However, the intermodal interference of the launched modes does not cause thermal gradients in the passive optical fiber. Upon propagation in the passive multimode optical fiber, the excited optical modes may lose mutual coherence, causing a reduction of contrast of the intermodal interference pattern along the doped core of the active optical fiber, effectively reducing modal instability in the active optical fiber.

Abstract: An array of laser diode emitters is used as an illumination source for a range imaging system. The laser diode emitters are disposed on a common substrate. When one of the emitters fails, the remaining emitters emit enough light to meet the output optical power specification. The emitters can be disposed with a tight spacing. The tight spacing facilitates packaging of the entire array into a compact single package on a common heat sink.

Abstract: A beam combiner may include source elements, each configured to output a beam of light locked at a center wavelength different from center wavelengths of other source elements. The beam combiner may include a dispersive element configured to combine the beams of light into a combined beam, and a beam separator configured to separate the combined beam into an output beam and a locking beam. The beam combiner may include a spatial filter configured to prevent crosstalk within the locking beam, and to redirect the locking beam to the source elements. The dispersive element may be configured to disperse the locking beam into constituent wavelength beams. Each constituent wavelength beam may be directed to a respective one of the source elements for locking that source element at its center wavelength, and may correspond in wavelength to the center wavelength of the respective source element.

Abstract: Cascaded optical harmonic generators and methods for cascaded optical harmonic generation are disclosed. Relative disposition of individual harmonic generators of a cascaded harmonic generator in an optical path of the fundamental optical beam may be reversed. In a third harmonic generator, the fundamental optical beam may enter the third harmonic crystal first, and the second harmonic crystal second. When the fundamental optical beam enters the third harmonic crystal first, the fundamental light may remain non-depleted by second harmonic generation process.

Abstract: Alignment of a multimode waveguide to a source of light or another waveguide is evaluated using a multi-wavelength light source and a modal decomposition processing of an intensity profile of a waveguide output beam, wherein inter-modal interference is averaged out over wavelength. Fitting a superposition of mode intensity profiles to a wavelength-averaged intensity profile of the output beam provides information about the modal composition of the output beam, which may be used to assess the alignment of the multimode waveguide with respect to the input light beam, and to provide a feedback for guiding a waveguide alignment process.

Abstract: A photovoltaic junction for a solar cell is provided. The photovoltaic junction has an intrinsic region comprising a multiple quantum well stack formed from a series of quantum wells separated by barriers, in which the tensile stress in some of the quantum wells is partly or completely balanced by compressive stress in the others of the quantum wells. The overall elastostatic equilibrium of the multiple quantum well stack may be ensured by engineering the structural and optical properties of the quantum wells only, with the barriers having the same lattice constant as the materials used in the oppositely doped semiconductor regions of the junction, or equivalently as the actual lattice size of the junction or intrinsic region, or the bulk or effective lattice size of the substrate. Alternatively, the barriers may contribute to the stress balance.

Abstract: New architectures for multicast switches, and other optical switches and splitters, that have substantially reduced insertion loss, crosstalk and better overall optical performance in comparison to existing optical switches and splitters. Optimized waveguide mesh layouts are used to substantially reduce the number of waveguide crossings, which reduces insertion loss. The reduction in the number of crossings also reduces the complexity of the mesh and provides better crossing angles to reduce crosstalk and other issues. Instead of crossing all of the waveguides connected between splitter outputs and switch inputs, the waveguides are crossed in sets of waveguides.

Abstract: A compact wavelength dispersing device and a wavelength selective optical switch based on the wavelength dispersing device is described. The wavelength dispersing device has a folding mirror that folds the optical path at least three times. A focal length of a focusing coupler of the device is reduced and the NA is increased, while the increased optical aberrations are mitigated by using an optional coma-compensating wedge. A double-pass arrangement for a transmission diffraction grating allows further focal length and overall size reduction due to increased angular dispersion.

Abstract: An optomechanical assembly for a photonic chip is disclosed. The optomechanical assembly may include a planar lightwave circuit optically coupled to a plurality of vertical coupling gratings on the photonic chip, to couple light between an optical connector abutting the planar lightwave circuit and the photonic chip.

Abstract: A tunable transmission optical filter is optically coupled between a laser section and semiconductor optical amplifier (SOA) section of a tunable laser device. The optical filter may be tuned to provide a high transmission near the lasing peak while suppressing a significant portion of back-propagating amplified spontaneous emission (ASE) of the SOA section. Without the optical filter, the laser output spectrum may develop side lobes of higher intensity after the ASE is amplified and reflected in the forward direction by the laser gain and mirror sections. While lessening the side lobes, the optical filter simultaneously transmits the laser peak for amplification by the SOA section.

Abstract: The number of wavelength selective switch (WSS) units in a WSS device can be doubled by using polarization properties of optical beams propagating through the WSS device. Beams from different WSS units are orthogonally polarized at the front end, propagated through collimator, wavelength dispersing element, and a focusing element, and impinge on a polarizing beamsplitter, which directs sub-beams at different polarizations to different directing elements of a director array. A polarization diversity configuration at the back end can be used to reduce polarization dependent loss.

Abstract: A leadframe-type packaged laser diode is provided, in which the laser diode chip is electrically decoupled from the package. A leadframe-type package including a two-dimensional grid of electrodes encapsulated in a molded plastic framework allows batch processing of one- or two-dimensional arrays of leadframes, the batch processing including laser diode chips attachment, wirebonding, and packaging, with subsequent breakout of individual packaged laser diodes from the one- or two-dimensional array.