David R Andersen

US Patent:

6396972, May 28, 2002

Filed:

Feb 9, 2000

Appl. No.:

09/501351

Inventors:

John ORourke - Los Altos Hills CA
David Andersen - Sunnyvale CA

Assignee:

Agilent Technologies, Inc. - Palo Alto CA

International Classification:

G02B 626

US Classification:

385 17, 385 18, 385 19

Abstract:

An optical switching arrangement, preferably an add/drop switch, provides a high degree of flexibility in manipulating optical signals by utilizing switching units that are mirror images of each other. The switching units are toggled between transmissive states and reflective states by the manipulation of index-matching fluid within trenches. In a first set of switching units, the trenches are offset in one direction relative to crosspoints of waveguides through which optical signals are propagated. In the second set of switching units, the trenches are offset in the opposite direction. As a result, the reflection characteristics of the first set of switching units are the mirror image of the reflection characteristics of the second set of switching units. In the preferred add/drop switching application, any one of a number of input ports can be optically coupled to any one of a number of drop ports and any one of a number of add ports can be optically coupled to any one of a number of output ports. Also in the preferred application, the paths from the input ports to the associated output ports are identical with respect to path lengths and the number of trenches that must be traversed, so that an optical signal will experience the same insertion loss regardless of the particular input-to-output path that it follows.

US Patent:

6459828, Oct 1, 2002

Filed:

Apr 29, 2000

Appl. No.:

09/561769

Inventors:

David Andersen - Sunnyvale CA

Assignee:

Agilent Technologies, Inc. - Palo Alto CA

International Classification:

G02B 626

US Classification:

385 17, 385 18, 385 16

Abstract:

An optical switch array has row and column waveguide segments, on a waveguide substrate. Each waveguide segment terminates in a trench positioned in one of two patterns. In the first pattern, the trenches are positioned along the diagonal while in the second pattern, the trenches are positioned in a regular array. The row and column waveguide segments are in fixed relation and generally parallel to the surface of the waveguide substrate. A heater substrate has heaters aligned to the waveguide substrate in accordance with the trenches. A liquid, disposable within the trenches, is responsive to the heaters. The liquid has an index of refraction such that optical transmission from a first selected waveguide segment to a second waveguide segment is determined by presence of the liquid within the trenches.

US Patent:

20040243827, Dec 2, 2004

Filed:

May 30, 2003

Appl. No.:

10/449575

Inventors:

Marcos Aguilera - Palo Alto CA, US
Minwen Ji - Sunnyvale CA, US
Mark Lillibridge - Mountain View CA, US
John MacCormick - San Francisco CA, US
Erwin Oertli - Mountain View CA, US
David Andersen - Cambridge MA, US
Michael Burrows - Palo Alto CA, US
Timothy Mann - Redwood City CA, US
Chandramohan Thekkath - Palo Alto CA, US

International Classification:

H04L009/00

US Classification:

713/200000

Abstract:

A method for managing access control of a resource includes storing a revocation list containing a list of revoked capabilities and their corresponding groups; storing a group list containing a list of valid groups; receiving a capability revocation request to revoke a specified capability; selecting a revocation method from among a plurality of revocation methods, including an individual capability revocation method and a group revocation method; revoking the specified capability by invalidating the group to which the specified capability belongs if the group revocation method is selected; and revoking the specified capability by invalidating only the specified capability if the individual capability revocation method is selected.

US Patent:

20040243828, Dec 2, 2004

Filed:

May 30, 2003

Appl. No.:

10/449576

Inventors:

Marcos Aguilera - Palo Alto CA, US
Minwen Ji - Sunnyvale CA, US
Mark Lillibridge - Mountain View CA, US
John MacCormick - San Francisco CA, US
Erwin Oertli - Mountain View CA, US
David Andersen - Cambridge MA, US
Michael Burrows - Palo Alto CA, US
Timothy Mann - Redwood City CA, US
Chandramohan Thekkath - Palo Alto CA, US

International Classification:

H04L009/00

US Classification:

713/200000

Abstract:

A system for protecting data integrity in a network attached block-device, such as a disk or a disk array, includes a capability issuer module coupled to a metadata server. The capability-issuer module creates capability data in accordance with a predetermined set of rules, and issues the capability data to the client over a secured channel. The capability data includes a group identifier, a capability identifier, a block-device identifier, a list of extents for specifying a range of blocks to which access is granted, an access mode for indicating the type of access allowed, and a cryptographic string for preventing forgery of capabilities by unauthorized parties. A capability checker module coupled to a network attached block-device verifies that the client's block access request is consistent with the capability data issued, and that the capability data is authentic. Upon verifying the client's capability data, the client's block access request is granted and executed at the network-attached block-device.

US Patent:

D2526891, Aug 21, 1979

Filed:

Mar 14, 1977

Appl. No.:

5/777307

Inventors:

Farouk Arjani - Foster City CA
Thomas J. Kramer - San Jose CA
Richard E. Johnson - Los Altos CA
Ralph M. Swan - Sunnyvale CA
David C. Andersen - Cupertino CA
David D. Pharmer - Gilroy CA

Assignee:

Artec International Corporation - Palo Alto CA

International Classification:

D1801

US Classification:

D18 2

US Patent:

42020042, May 6, 1980

Filed:

Sep 20, 1978

Appl. No.:

5/944097

Inventors:

David C. Andersen - Los Altos CA

International Classification:

H01L 2714

US Classification:

357 30

Abstract:

A crystal of a semiconductor material has an electrically conducting loom assembly embedded therein, whereby the crystal and loom assembly define a unit which converts light or other electromagnetic radiation into an electrical current for flow to an external electrical circuit. The loom assembly has a plurality of electrodes coated with another semiconductor material so that the semiconductor materials define a plurality of n-p junctions within the crystal. Radiation absorbed by the crystal will liberate electrons which will flow across the junctions and along electrical paths formed in the loom assembly to conductor means which can be connected to an external electrical circuit. The loom assembly comprises a plurality of very small loom units comprised of pairs of spaced electrodes, one of the electrodes of each loom unit having a coating of a semiconductor material in contact with the semiconductor material of the crystal. The loom assembly can be made by laser cut tooling and the crystal can be grown on the loom assembly. The crystal can be mounted in any suitable manner to receive solar energy, such as in optical alignment with a lens system or at the focus of a curved mirror.

US Patent:

D2522730, Jul 3, 1979

Filed:

Mar 14, 1977

Appl. No.:

5/777114

Inventors:

Farouk Arjani - Foster City CA
Thomas J. Kramer - San Jose CA
Richard E. Johnson - Los Altos CA
Ralph M. Swan - Sunnyvale CA
David C. Andersen - Cupertino CA
David D. Pharmer - Gilroy CA

Assignee:

Artec International Corporation - Palo Alto CA

International Classification:

D1402

US Classification:

D14 46

US Patent:

20220353726, Nov 3, 2022

Filed:

Jul 14, 2022

Appl. No.:

17/864718

Inventors:

- Lewisville TX, US
J. Roy Pottle - Wellesley MA, US
Peter C. Barnett - Mason OH, US
David Andersen - Dillon CO, US
Jamie Gordon Nichol - Arlington MA, US
Sangsoo Kim - Seoul, KR

International Classification:

H04W 24/10
H04B 1/10

Abstract:

An electronic messaging device includes a receiver configured to receive a message at one of a first operational frequency and second operational frequency. The messaging device can added to a message distribution group comprising a plurality of existing messaging devices. A test communication can be sent through a coupling to test an operation of the messaging device and confirming the addition of the messaging device to the message distribution group without communicating with the existing messaging devices.