David J Dougherty

US Patent:

6697553, Feb 24, 2004

Filed:

Feb 15, 2002

Appl. No.:

10/077581

Inventors:

Jyoti Kiron Bhardwaj - Cupertino CA
Robert James Brainard - Sunnyvale CA
David J. Chapman - San Jose CA
Douglas E. Crafts - San Jose CA
David Dougherty - Sunnyvale CA
Erik W. Egan - Oakland CA
James F. Farrell - San Jose CA
Mark B. Farrelly - San Jose CA
Niranjan Gopinathan - Santa Clara CA
Kenzo Ishida - Saratoga CA
David K. Nakamoto - Sunnyvale CA
Thomas Thuan Nguyen - San Jose CA
Suresh Ramalingam - Fremont CA
Steven M. Swain - San Jose CA
Sanjay M. Thekdi - Santa Clara CA
Anantharaman Vaidyanathan - San Jose CA
Hiroaki Yamada - San Jose CA
Yingchao Yan - Milpitas CA

Assignee:

JDS Uniphase Corporation - San Jose CA

International Classification:

G02B 634

US Classification:

385 37, 385 24, 385 46, 385 43

Abstract:

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).

US Patent:

6947653, Sep 20, 2005

Filed:

Oct 12, 2001

Appl. No.:

09/977065

Inventors:

Jyoti Kiron Bhardwaj - Cupertino CA, US
Robert James Brainard - Sunnyvale CA, US
David Dougherty - Sunnyvale CA, US
Erik W. Egan - Oakland CA, US
Niranjan Gopinathan - Santa Clara CA, US
David K. Nakamoto - Sunnyvale CA, US
Thomas Thuan Nguyen - San Jose CA, US
Sanjay M. Thekdi - Santa Clara CA, US
Anantharaman Vaidyanathan - San Jose CA, US
Hiroaki Yamada - San Jose CA, US
Yingchao Yan - Milpitas CA, US

Assignee:

JDS Uniphase Corporation - San Jose CA

International Classification:

G02B006/10
G02B006/13
G02F001/295

US Classification:

385129, 385 10, 385 11, 385132, 438 31

Abstract:

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.

US Patent:

7106930, Sep 12, 2006

Filed:

Jun 28, 2004

Appl. No.:

10/878935

Inventors:

Jinxi Shen - San Ramon CA, US
Anca L. Sala - Sunnyvale CA, US
David J. Dougherty - Mountain View CA, US
David Funk - San Jose CA, US
Douglas E. Crafts - San Jose CA, US
Barthelemy Fondeur - Mountain View CA, US
Pang-Chen Sun - San Diego CA, US

Assignee:

JDS Uniphase Corporation - Milpitas CA

International Classification:

G02B 6/34

US Classification:

385 37, 385 31, 385 32, 385 39, 385 46, 385 50

Abstract:

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.

US Patent:

7171085, Jan 30, 2007

Filed:

Jul 29, 2003

Appl. No.:

10/629143

Inventors:

David J. Dougherty - Mountain View CA, US
Pang-Chen Sun - San Diego CA, US
Duncan W. Harwood - Santa Clara CA, US

Assignee:

JDS Uniphase Corporation - Milpitas CA

International Classification:

G02B 6/26
G02B 6/00

US Classification:

385 48, 385 11, 385 42

Abstract:

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.

US Patent:

7715671, May 11, 2010

Filed:

May 14, 2007

Appl. No.:

11/748036

Inventors:

Barthelemy Fondeur - San Jose CA, US
David J. Dougherty - Mountain View CA, US

Assignee:

JDS Uniphase Corporation - Milpitas CA

International Classification:

G02B 6/34
G02B 6/26

US Classification:

385 37, 385 31, 385 32

Abstract:

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.

US Patent:

8213752, Jul 3, 2012

Filed:

Jun 9, 2009

Appl. No.:

12/480956

Inventors:

David J. Chapman - San Jose CA, US
David J. Dougherty - Pleasanton CA, US

International Classification:

G02B 6/26

US Classification:

385 17

Abstract:

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.

US Patent:

20030174949, Sep 18, 2003

Filed:

Mar 15, 2002

Appl. No.:

10/099565

Inventors:

Jyoti Bhardwaj - Cupertino CA, US
David Dougherty - Mountain View CA, US
Venkatesan Murali - San Jose CA, US
Hiroaki Yamada - San Jose CA, US

Assignee:

Scion Photonics, Inc. - Milpitas CA

International Classification:

G02B006/34
G02B006/293
G02B006/26

US Classification:

385/037000, 385/024000, 385/015000

Abstract:

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.

US Patent:

20070223552, Sep 27, 2007

Filed:

Nov 17, 2006

Appl. No.:

11/561132

Inventors:

Martin Muendel - Oakland CA, US
David Dougherty - Mountain View CA, US
Matthew Peters - Menlo Park CA, US
Victor Rossin - Mountain View CA, US
Robert Sargent - Santa Rosa CA, US
Len Marabella - Santa Rosa CA, US
Kuochou Tai - Fremont CA, US
Bruno Acklin - Mountain View CA, US
Yongan Wu - San Jose CA, US
Kenneth Dzurko - Monte Sereno CA, US

Assignee:

JDS Uniphase Corporation - Milpitas CA

International Classification:

H01S 5/00

US Classification:

372050120

Abstract:

The invention relates to high power semiconductor lasers based on a laser diode array waveguide grating (DAWG) in which the wavelength is stabilized using an array waveguide grating (AWG) in an external cavity configuration. Another aspect of the present invention relates to techniques for efficiently coupling optical gain element arrays to an AWG. Another feature provides for the efficient and brightness-conserving combination of multiple high power DAWG lasers into a single output.