Jds Uniphase Corporation

Other

David J Dougherty

Jyoti Kiron Bhardwaj

Hiroaki Yamada

Douglas E Crafts

Barthelemy Fondeur

Robert Brainard

Daniel Yousef Al-Salameh

Sanjay M Thekdi

Zi-Wen Dong

Anantharaman Vaidyanathan

David J Chapman

Pang-Chen Sun

Thomas Nguyen

David K Nakamoto

Erik W Egan

Niranjan Gopinathan

Yingchao Yan

Suresh Ramalingam

Venkatesan Murali

Karl M Kissa

Jinxi Shen

Kenzo Ishida

James F Farrell

Steven M Swain

Anca L Sala

Mark Brian Farrelly

Duncan Harwood

David Funk

A rotatable plow shovel apparatus for clearing a path without having to lift includes a plow blade and a shaft housing having a curved front face coupled to a back side of the plow blade. A shaft aperture extends through a top side of the shaft housing to proximal a bottom side and the back face has a plurality of adjustment apertures extending through to the shaft aperture. A handle shaft has a vertical engagement portion rotatably engaged within the shaft aperture and an angled extension portion coupled to the engagement portion. A locking pin is coupled to the engagement portion and is selectively engageable with each of the plurality of adjustment apertures of the shaft housing to lock the handle shaft in a straight position, at least one alternative left tilt position, and at least one alternative right tilt position.

Rotatable plow shovel apparatus

The invention relates to an optical device including a passive high confinement waveguide, such as of silicon-rich silicon nitride, on an electro-optic substrate, like lithium niobate, optically coupled to a waveguide in the electro-optic substrate. A wide range of electro-optic devices are enabled by this high confinement waveguide structure, including: directional couplers, compact tap couplers, folded electro-optic devices, electro-optic modulators including ring resonators, electro-optic gratings. Further applications enabled by the present invention include hybrid passive planar lightwave circuits (PLC) integrated with electro-optically active waveguides, using the high confinement waveguide as an intermediary waveguide to transfer optical power between the passive and active components.

High confinement waveguide on an electro-optic substrate

A coherent planar lightwave circuit (PLC) optical mixer chip is described comprising a matched pair of symmetrical four-coupler interferometers for in-phase and in-quadrature detection of two polarization components of light using a polarization diversity arrangement. The waveguide structure of the chip is symmetrical about two orthogonal central axes of the chip, whereby the effect of temperature gradients on the mixer is reduced. A light traveling from an input to an output of any of the two interferometers is cross-coupled by one of the two couplers it passes through, and is bar-coupled by the other of the two couplers, so as to compensate for polarization, wavelength, and manufacturing process dependence of bar-coupling with that of cross-coupling.

Coherent optical mixer and a method of coherent detection of light

A method and apparatus for monitoring spectral tilt uses an arrayed waveguide grating (AWG) to separate a multiplexed optical signal having a plurality of wavelength channels into a plurality of sub-bands, where each sub-band spans a different wavelength range and includes more than one wavelength channel. A photodetector array is provided to measure the optical power in each of the sub-bands, while control electronics calculate spectral tilt of the multiplexed optical signal using the measured optical power in each of the sub-bands. The spectral tilt monitor in accordance with the instant invention provides spectral resolution, increased monitoring speeds, and decreased manufacturing costs.

Spectrally resolved fast monitor

The invention relates to an asymmetric Mach Zehnder Interferometer (MZI) having a reduced drive voltage, coupled to a compact low-loss arrayed waveguide grating (AWG) to provide a broader passband with low ripple. The integrated device has a compact stackable design for improved manufacturing yield. Inputs and outputs of the device are disposed in alignment on opposite sides of a silicon chip with the MZI having an opposite curvature to the AWG. To achieve this alignment, waveguide arms of the MZI are crossed without coupling between them before the optical signal is combined and coupled into the AWG.

Asymmetric Mach-Zehnder interferometer having a reduced drive voltage coupled to a compact low-loss arrayed waveguide grating

A polarization compensated planar waveguide branch is disclosed having a planar optical trunk waveguide for transporting a linearly un-polarized optical signal having TE and TM modes. A planar optical branch waveguide, capable of supporting TE and TM modes is optically coupled to the trunk waveguide such that at least a portion of an optical signal propagating within the trunk waveguide will couple into the branch waveguide with an undesired imbalance, having stronger TM mode coupling than TE mode coupling for the at least the portion of the optical signal which couples into the branch waveguide from the trunk waveguide. A portion of said branch waveguide downstream from a region where coupling takes place between the trunk and branch waveguides or a waveguide portion optically coupled thereto, receives the at least a portion of the optical signal, and has at least a predetermined bend with a predetermined radius for compensating for the unwanted imbalance in the TM and TE mode caused by light optically coupling into the branch from the trunk waveguide.

Polarization compensated optical tap

A demultiplexer/multiplexer is disclosed wherein an arrayed waveguide grating having a reflector at an end includes selectable signal path blockers. The arrayed waveguide device has a common input/output port for launching radiation in the form of an input signal having n wavelengths therein and for receiving back via the reflector at the input/output port a selected channel of the input signal. In operation a multiplexed signal have n channels is launched therein and a selected channel is output for analysis or further processing.

Dynamic optical demultiplexer/multiplexer formed within a PLC

A planar lightwave circuit generalized for handling any given band of multiple bands of a wavelength range, including a first grating element handling a first group of bands; and a second grating element handling a second group of bands. The first and second groups of bands overlap in the wavelength range, and may be spaced apart by a fixed wavelength value. By providing two periodic grating elements handling alternating bands, their free spectral range is allowed to expand, improving their roll-off characteristics. By providing separate inputs for each band, wavelength accuracy can be improved. Device flexibility can be further improved by using switch and interleaver fabrics at the inputs and outputs. The resultant device, generalized to handle any given band within a wavelength range, eliminates the need for separate component design and inventory tracking otherwise necessary.

Multi-band arrayed waveguide grating with improved insertion loss and wavelength accuracy

A planar lightwave circuit includes at least one optical waveguide core, and at least one feature proximate the core having a stress-engineered property to balance stress and therefore minimize birefringence affecting the core. A protective passivation layer is formed over the core and the feature to be substantially non-interfering with the balanced stress provided by the feature. The stress balancing feature may be an overcladding layer formed over the core, doped to have a coefficient of thermal expansion approximately matched to that of an underlying substrate, to symmetrically distribute stress in an undercladding between the overcladding and the substrate, away from the core. The protective passivation layer is formed to have a coefficient of thermal expansion approximately matched to that of the overcladding. In one exemplary embodiment, the passivation layer is formed from silicon nitride. Related concepts of stress release grooves, and core overetching, are also disclosed.

Waveguide stress engineering and compatible passivation in planar lightwave circuits

A planar lightwave circuit includes an arrayed waveguide grating (AWG), with input and output waveguides, partially curved array waveguides with respective length differences, and planar waveguide regions for focusing optical energy between the input/output and array waveguides. Optimal waveguide widths and spacing along the planar waveguide region facets are disclosed, which are largely determinative of AWG size and optical performance. Also disclosed are optimal cross-sectional waveguide dimensions (e.g., width and height); modified index of refraction difference between the waveguide core and cladding regions; and optimal array waveguide lengths, path length differences, and free spectral range. These features, especially when combined with advanced fiber attachment, passivation and packaging techniques, result in high-yield, high-performance AWGs (both gaussian and flattop versions).

Compact, low insertion loss, high yield arrayed waveguide grating

Growing community of inventors

Mountain View, CA, United States of America

David J Dougherty