Jds Uniphase Corporation

Hgst Netherlands, B.v.

Workday, Inc.

Thomas Nguyen

Robert Brainard

Sanjay M Thekdi

Anantharaman Vaidyanathan

Jyoti Kiron Bhardwaj

David J Dougherty

Zi-Wen Dong

Hiroaki Yamada

David K Nakamoto

Erik W Egan

Niranjan Gopinathan

Yingchao Yan

Suresh Ramalingam

Douglas E Crafts

Barthelemy Fondeur

Kris Victor Schouterden

Vedantham Raman

David H Jen

James F Farrell

Kenzo Ishida

Steven M Swain

Anca L Sala

David J Chapman

Mark Brian Farrelly

Francis Wang

Jorge F Escobar

Duncan Harwood

John W Yates

Scott McCoy

Annamica Bhan

Ian Hutagalung

Mark Hampton

Lian Zheng

A system for determining access for a hypercube includes an interface configured to receive a request for access from a user to data in a location in a hypercube; receive a tree structure with subcubes of the hypercube arranged in a hierarchical structure; and receive a user permission list, wherein an element of the user permission list comprises a permission, a root node, and a set of pruned nodes. The system also includes a processor configured to determine a user permission associated with the data in the location of the hypercube using the user permission list; and provide an indication of the user permission.

Systems and methods for manipulating pruned tree sets to determine access regions in a hypercube

Cleaning a recording head slider in-drive during operation is accomplished by periodically performing a series of full stroke seek operations, whereby liquid contaminants that may have migrated to the head slider are flung from the slider and liquid from the disk surface may be adsorbed onto the slider for removal by way of flinging. Consequently, head-disk spacing may be stabilized and data write operations improved. Furthermore, the series of full stroke seek operations may be performed at predetermined intervals, and for a predetermined period of time. However, the series may be interrupted by a client request, and continued thereafter, so as not to affect the operational status of the recording system.

Self-cleaning recording heads based on actuator seek profile

The invention relates to a variable optical attenuator constructed as a Mach Zehnder planar lightwave circuit, particularly including a channel waveguide support structure for heat isolation and stress relief to reduce polarization dependent loss (PDL) and power consumption in the device. Power reduction trenches comprise longitudinal segments having small stress relief pillars of cladding material left in between them in the etching process. The waveguides of the MZI are supported by a main pillar structure and integral stress relief pillars which remain after removal of the trenches. The waveguide is surrounded by air on three sides for improved heat isolation. The performance of the present invention shows substantial improvement in PDL and extinction ratio over the prior art continuous trench design, and also, to a smaller degree, over the case where power reduction trenches are not used at all. Segmented trenches appear to allow for the lowest stress on the two waveguide arms of all the cases including no trench and trenched devices.

Planar lightwave circuit variable optical attenuator

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

San Jose, CA, United States of America

Thomas Nguyen