Liang Zhao

US Patent:

6697552, Feb 24, 2004

Filed:

May 3, 2001

Appl. No.:

09/848093

Inventors:

Kenneth McGreer - Fremont CA
Liang Zhao - San Jose CA
Jane Lam - San Jose CA
Hao Xu - Sunnyvale CA

Assignee:

Lightwave Microsystems Corporation - San Jose CA

International Classification:

G02B 634

US Classification:

385 37, 385 43, 385 50

Abstract:

The present invention generally provides an optical wavelength router that includes at least one dendritic taper region. The dendritic taper region includes at least one dendritic taper which has a trunk and at least one branch optically coupled to the trunk. In addition to the dendritic taper region, the optical wavelength router includes at least one input waveguide, a input slab waveguide, an arrayed waveguide grating, an output slab waveguide, and at least one output waveguide. The improved optical wavelength router provides a wide passband width without a substantial effect on insertion loss.

US Patent:

6735363, May 11, 2004

Filed:

Mar 8, 2002

Appl. No.:

10/096124

Inventors:

Kenneth McGreer - Fremont CA
Liang Zhao - Sunnyvale CA
Jane Lam - San Jose CA

Assignee:

Lightwave Microsystems Corporation - San Jose CA

International Classification:

G02B 634

US Classification:

385 37, 385 24, 385 46

Abstract:

An optical integrated circuit (OIC) or optical apparatus upon which a waveguide-grating router (WGR) device is fashioned is provided, where the circuit is configured to optimize a passband for each channel transmitted on an output waveguide. The WGR has two or more waveguides of varying widths optically coupled to a slab waveguide. The widths can be configured to facilitate producing a substantially uniform frequency-limited bandwidth, a substantially uniform wavelength-limited bandwidth, a substantially uniform isolation value, and/or a substantially uniform value for insertion loss between the output waveguides, which in turn facilitates producing optical data communication devices with more consistent transmission parameters and higher quality. In addition to various widths, the shape of the delivering end of a slab waveguide can be fashioned to further improve the consistency and quality of such parameters.

US Patent:

6823103, Nov 23, 2004

Filed:

Sep 18, 2001

Appl. No.:

09/955630

Inventors:

Jane Lam - San Jose CA
Liang Zhao - San Jose CA
Kenneth McGreer - Fremont CA
Hao Xu - Sunnyvale CA
Wayne Wai Wing Lui - Fremont CA

Assignee:

Lightwave Microsystems Corporation - San Jose CA

International Classification:

G02B 628

US Classification:

385 24, 385 15, 385 31

Abstract:

The invention relates to an optical device which carries multiple optical signals where the optical device has a plurality of distal waveguides some of which may be configured to control insertion loss among the multiple optical signals.

US Patent:

6850670, Feb 1, 2005

Filed:

Jun 28, 2001

Appl. No.:

09/894049

Inventors:

Farnaz Parhami - Fremont CA, US
Liang Zhao - San Jose CA, US
Fan Zhong - Fremont CA, US

Assignee:

Lightwave Microsytstems Corporation - San Jose CA

International Classification:

G02B 634

US Classification:

385 37, 385 11

Abstract:

A method and apparatus for controlling waveguide birefringence by selection of a waveguide core width for a tuned top clad is described herein. A tuned top cladding describes a pre-existing dopant concentration within a top cladding material. Given a tuned top cladding composition, a width of the waveguide core is pre-selected such that birefringence is minimized, i. e. , a zero, or near zero. The desirable width of the waveguide core is determined by calculating the distribution of stress in the top cladding over a change in temperature. From this distribution of stress, a relationship between the polarization dependent wavelength and variable widths of the waveguide in the arrayed waveguide grating are determined. This relationship determines a zero value, or near zero value, of polarization dependent wavelength for a given range of waveguide widths. Accordingly, the width of the waveguide may be selected such that the polarization dependent wavelength is minimized.

US Patent:

7182878, Feb 27, 2007

Filed:

Feb 6, 2004

Appl. No.:

10/773802

Inventors:

Jongik Won - Pleasanton CA, US
Calvin Ka Kuen Ho - San Jose CA, US
Fan Zhong - Fremont CA, US
Liang Zhao - San Jose CA, US

Assignee:

Lightwave Microsystems Corporation - San Jose CA

International Classification:

B29D 11/00

US Classification:

216 24, 216 60, 216 72, 216 79

Abstract:

This relates to optical devices such as planar light-wave components/circuits which are designed to have a high waveguide pattern density effecting a higher etch selectivity and overall improved dimensional control of the functional waveguides on the optical device.

US Patent:

7194162, Mar 20, 2007

Filed:

Feb 22, 2002

Appl. No.:

10/082603

Inventors:

Ming Yan - Pleasanton CA, US
Liang Zhao - San Jose CA, US
Hao Xu - Sunnyvale CA, US

Assignee:

NeoPhotonics Corporation - San Jose CA

International Classification:

G02B 6/34
G02B 6/00

US Classification:

385 37, 385 31

Abstract:

A method of optimizing a filter response of an arrayed waveguide grating is disclosed. The method includes the step of measuring a respective phase error of a plurality of waveguide cores of the arrayed waveguide grating. Once the phase error is measured, a respective optical path length of the cores is adjusted in accordance with the respective phase error of the cores. Optical path length is adjusted by adjusting a respective refractive index of the cores. The respective optical path length can be controlled to nanometer accuracies by adjusting the respective refractive index of the cores.

US Patent:

7447394, Nov 4, 2008

Filed:

May 24, 2007

Appl. No.:

11/753074

Inventors:

Calvin Ho - San Jose CA, US
Brian McGinnis - Livermore CA, US
Wilson Long - San Jose CA, US
Ed Fontecha - San Jose CA, US
David J. Quirke - San Jose CA, US
Thomas S. Tarter - San Jose CA, US
Sam Seto - Cupertino CA, US
Liang Zhao - Sunnyvale CA, US

Assignee:

Neophotonics Corporation - San Jose CA

International Classification:

G02B 6/12
G02B 6/28
G02B 6/34

US Classification:

385 14, 385 24, 385 37

Abstract:

An optical device with a non-rectilinearly shaped optical integrated circuit over a substantially flat portion of a riser, the riser also equipped with a relief structure that is in thermal contact with a stabilizing brace that is in turn connected to two portions of the non-rectilinearly shaped optical integrated circuit. The non-rectilinearly shaped optical integrated circuit exhibits reduced center wavelength drift.

US Patent:

7609917, Oct 27, 2009

Filed:

Mar 28, 2008

Appl. No.:

12/079930

Inventors:

Farnaz Parhami - Fremont CA, US
Liang Zhao - Sunnyvale CA, US
Fan Zhong - Fremont CA, US

Assignee:

Lightwave Microsystems Corporation - San Jose CA

International Classification:

G02B 6/12
G02B 6/10
G02B 6/34

US Classification:

385 14, 385 37, 385129, 385131

Abstract:

A method and apparatus for controlling waveguide birefringence by selection of a waveguide core width for a tuned top clad is described herein. In one example, a dopant concentration within a top cladding material is between 3-6% (wt. ). Given a tuned top cladding composition, a width of the waveguide core is pre-selected such that birefringence is minimized, i. e. , a zero, or near zero. The desirable width of the waveguide core is determined by calculating the distribution of stress in the top cladding over a change in temperature. From this distribution of stress, a relationship between the polarization dependent wavelength and variable widths of the waveguide in the arrayed waveguide grating are determined. This relationship determines a zero value, or near zero value, of polarization dependent wavelength for a given range of waveguide widths. Accordingly, the width of the waveguide may be selected such that the polarization dependent wavelength is minimized.