Daniel A Francis

US Patent:

6351260, Feb 26, 2002

Filed:

Mar 4, 1999

Appl. No.:

09/262398

Inventors:

David S. Graham - San Francisco CA
Daniel A. Francis - San Francisco CA

Assignee:

Poa Sana, Inc. - San Jose CA

International Classification:

G09G 500

US Classification:

345179, 345173, 345175, 345176, 345104

Abstract:

A user input device for an electronic device is disclosed. The user input device provides positional information using a grid of light. The grid of light is produced from a light source and waveguides. The grid of light is also received and processed using waveguides and a light detector. Optionally, optics may be used to enhance the operation of the user input device. The user input device is particularly suited for use as a user input device for a computer system or the like.

US Patent:

6445495, Sep 3, 2002

Filed:

Mar 22, 1999

Appl. No.:

09/273813

Inventors:

Jeffrey D. Walker - El Cerrito CA
Sol P. Dijaili - Moraga CA
Daniel A. Francis - Oakland CA

Assignee:

Genoa Corporation - Fremont CA

International Classification:

H01S 318

US Classification:

359344

Abstract:

A tunable-gain lasing semiconductor optical amplifier comprises a vertical-lasing semiconductor optical amplifier that includes a tunable region which allows the gain of the vertical-lasing semiconductor optical amplifier to be tuned. The tunable region comprises a region whose loss and/or phase may be tuned by adjusting a physical characteristic of the region. For example, the region may comprise a liquid crystal layer whose transmissivity may be adjusted by applying different voltages across the layer to adjust the reflectivity of a cavity mirror, or a cavity mirror whose reflectivity may be adjusted by ion implantation. In an alternative embodiment of this invention, the tunable-gain lasing semiconductor optical amplifier comprises a tunable loss element in series after the gain-clamped semiconductor optical amplifier.

US Patent:

6647041, Nov 11, 2003

Filed:

May 26, 2000

Appl. No.:

09/580322

Inventors:

Ashish K. Verma - San Jose CA
Arnold C. Chen - Fremont CA
Daniel A. Francis - Oakland CA

Assignee:

Finisar Corporation - Sunnyvale CA

International Classification:

H01S 500

US Classification:

372 45, 372 43, 372 50

Abstract:

A monolithic semiconductor device extends primarily along a vertical direction and includes the following layers. A first semiconductor layer and a second semiconductor layer form an active region between them. A third semiconductor layer is doped the same type as the second semiconductor layer but is lattice mismatched to the second semiconductor layer. The lattice mismatch results in unwanted electrical effects. An additional doping layer, preferably a delta doping layer, is located in close proximity to the interface between the second and third semiconductor layers. The delta doping layer mitigates the unwanted electrical effects introduced by the lattice mismatch. In a preferred embodiment, the device further includes a bottom mirror layer and a top mirror layer, which together form a laser cavity including the active region.

US Patent:

6977424, Dec 20, 2005

Filed:

Mar 18, 2003

Appl. No.:

10/392599

Inventors:

Jeffrey D. Walker - El Cerrito CA, US
Daniel A. Francis - Oakland CA, US
Peter W. Evans - Tracy CA, US
Paul Liu - Fremont CA, US

Assignee:

Finisar Corporation - Sunnyvale CA

International Classification:

H01L031/0232

US Classification:

257432, 257623, 257625, 257 80, 257 81, 257 82, 257 12

Abstract:

An electrically pumped optical device includes a semiconductor active region and a backward diode. Both of these structures are located in the current path of the optical device, which is oriented primarily vertically. The active region has a finite extent along at least one lateral dimension. The overall structure improves the electrical performance of the device.

US Patent:

6980577, Dec 27, 2005

Filed:

Mar 18, 2003

Appl. No.:

10/392671

Inventors:

Daniel A. Francis - Oakland CA, US
Chris Decker - Danville CA, US

Assignee:

Finisar Corporation - Sunnyvale CA

International Classification:

H01S005/00

US Classification:

372 50, 372 43, 372 99, 372107

Abstract:

A vertical laser cavity includes a non-planar top mirror in order to improve the optical performance of the laser cavity. In one approach, the top mirror is curved to form a plano-concave geometry with the bottom mirror, as opposed to the typical plano—plano geometry. This can reduce diffraction losses and otherwise improve optical performance.

US Patent:

7057803, Jun 6, 2006

Filed:

Jun 30, 2004

Appl. No.:

10/882444

Inventors:

Richard P. Ratowsky - Berkeley CA, US
Ashish K. Verma - San Jose CA, US
Daniel A. Francis - Oakland CA, US

Assignee:

Finisar Corporation - Sunnyvale CA

International Classification:

H01S 3/00

US Classification:

359344

Abstract:

Systems and methods for extending a linear range of a semiconductor optical amplifier (SOA). A feedback layer is included in an SOA. The optical mode of the SOA is distributed between the feedback layer and the active region. As output optical power increases, the mode confinement of the active region increases and the mode is drawn from the feedback layer into the active region. The increase in the mode confinement offsets a loss of material gain such that the linear range of the SOA is extended. In one embodiment, the modal gain increases an higher output optical powers.

US Patent:

7099075, Aug 29, 2006

Filed:

Sep 3, 2004

Appl. No.:

10/934603

Inventors:

Richard P. Ratowsky - Berkeley CA, US
Daniel A. Francis - Oakland CA, US
Ashish K. Verma - San Jose CA, US

Assignee:

Finisar Corporation - Sunnyvale CA

International Classification:

H01S 3/00
H01S 5/125

US Classification:

359344, 372 5011

Abstract:

Systems and methods for tuning a DBR stack for an optical amplifier. The DBR layers in a mirror of the optical amplifier have a duty cycle that can be altered to tune a location of a channel drop in a gain spectrum. In addition to changing the duty cycle, the DBR stacks can be segmented. The segmented DBR stacks and/or the selected duty cycle tunes a location of a channel drop outside of a range of wavelengths of interest.

US Patent:

7149236, Dec 12, 2006

Filed:

Oct 22, 2003

Appl. No.:

10/691376

Inventors:

Ashish K. Verma - San Jose CA, US
Arnold C. Chen - Fremont CA, US
Daniel A. Francis - Oakland CA, US

Assignee:

Finisar Corporation - Sunnyvale CA

International Classification:

H01S 5/00

US Classification:

372 50124, 372 4401, 372 4501, 372 5022, 372 4301

Abstract:

Optoelectronic devices, such as optical transmitters and optical amplifiers, are provided. The optoelectronic devices are suitable for use in connection with optical communications systems, and related components and devices, such as may be used in the transmission, reception and processing of data and other information. The optoelectronic devices are implemented as various types of semiconductors. The form, structure, properties and functionality of a particular optoelectronic semiconductor device are determined with reference to the application(s) in connection with which the optoelectronic device is to be employed.