Anthony Edgar Ho

US Patent:

6452922, Sep 17, 2002

Filed:

Dec 23, 1998

Appl. No.:

09/219018

Inventors:

Anthony Ho - Fremont CA

Assignee:

Nortel Networks Limited - St. Laurent

International Classification:

H04L 1266

US Classification:

370352, 370237

Abstract:

An apparatus causes alternate connection of a telephone call directed to an IP network if the quality of service provided by the IP network is less than a predetermined threshold. A network monitor measures a transmission rating factor for the IP network. An IP network interface, coupled to the network monitor, an originating system, and the IP network, receives the telephone call for a dialed number from the originating system. The IP network interface causes the originating system to connect the telephone call through a first network if the measured transmission rating factor for the IP network is less than the desired transmission rating factor, and connects the telephone call through the IP network otherwise.

US Patent:

6862302, Mar 1, 2005

Filed:

Oct 31, 2002

Appl. No.:

10/285105

Inventors:

Yew-Tai Chieng - Singapore, SG
Anthony Ho - Richmond CA, US
John Hsieh - Cupertino CA, US
Chun Lei - Arcadia CA, US
Jan Lipson - Cupertino CA, US
Jeff Price - Merrillville IN, US
Andreas Weber - Los Altos CA, US

Assignee:

Finisar Corporation - Sunnyvale CA

International Classification:

H01S003/13

US Classification:

372 2902, 372 29015, 372 25, 372 3807, 359152, 359180

Abstract:

A method of maintaining desirable optical performance of optical emitters over temperature variations is disclosed. The optical performance of an optical emitter in terms of power, extinction ratio, jitter, mask margin and general fiber optic transmitter eye quality can be maintained by the present invention over a wide range of temperatures. Advantageously, the present invention enables the use of inexpensive optical emitters in optoelectronic transceivers and optoelectronic transmitters.

US Patent:

7035300, Apr 25, 2006

Filed:

Nov 4, 2003

Appl. No.:

10/700845

Inventors:

James Stewart - San Jose CA, US
Lucy G. Hosking - Santa Cruz CA, US
Anthony Ho - Richmond CA, US
Andreas Weber - Los Altos CA, US

Assignee:

Finisar Corporation - Sunnyvale CA

International Classification:

H01S 3/04

US Classification:

372 34, 372 36

Abstract:

A method for calibrating a multi-channel laser emitter in an optoelectronic transceiver or an optoelectronic transmitter for a first wavelength includes monitoring the wavelength of optical signals from the laser emitter while varying its temperature as well as other operating conditions, and then storing calibration information in the memory of a microprocessor. The initial values of the calibrating procedure are reset and the calibrating procedure is repeated to obtain calibration information for a next desired wavelength.

US Patent:

7039082, May 2, 2006

Filed:

Dec 2, 2003

Appl. No.:

10/725871

Inventors:

James Stewart - Burlingame CA, US
Lucy G. Hosking - Santa Cruz CA, US
Anthony Ho - Sunnyvale CA, US
Andreas Weber - Los Altos CA, US

Assignee:

Finisar Corporation - Sunnyvale CA

International Classification:

H01S 3/04

US Classification:

372 34, 372 36

Abstract:

A method for calibrating a multi-channel laser emitter in an optoelectronic transceiver or an optoelectronic transmitter for a first wavelength includes monitoring the wavelength of optical signals from the laser emitter while varying its temperature as well as other operating conditions, and then storing calibration information in the memory of a microprocessor. The initial values of the calibrating procedure are reset and the calibrating procedure is repeated to obtain calibration information for a next desired wavelength.

US Patent:

7058099, Jun 6, 2006

Filed:

Nov 4, 2003

Appl. No.:

10/700981

Inventors:

James Stewart - San Jose CA, US
Lucy G. Hosking - Santa Cruz CA, US
Anthony Ho - Richmond CA, US
Andreas Weber - Los Altos CA, US

Assignee:

Finisar Corporation - Sunnyvale CA

International Classification:

H01S 3/13
H01S 3/98

US Classification:

372 32, 372 18

Abstract:

A method for compensating for wavelength drift in a fiber-optic laser transmitter includes 1) controlling a temperature within the optoelectronic assembly at a defined level; 2) driving the optoelectronic assembly to emit light, wherein the emitted light has a wavelength that is within a channel of operation, the channel of operation including a range of wavelengths centered around a channel center wavelength; 3) accessing from memory within the optoelectronic assembly a control value associated with the temperature of the optoelectronic assembly at defined points within an operational lifetime of the optoelectronic assembly; and 4) recalculating the defined level by reference to the control value, whereby a wavelength of the optoelectronic assembly is maintained within the channel of operation despite an expected drift of wavelength.

US Patent:

7155133, Dec 26, 2006

Filed:

Mar 18, 2002

Appl. No.:

10/101258

Inventors:

James Stewart - San Jose CA, US
Anthony Ho - Sunnyvale CA, US
Rudolf J. Hofmeister - Sunnyvale CA, US
Darin James Douma - Monrovia CA, US
Lucy G. Hosking - Santa Cruz CA, US
Andreas Weber - Los Altos CA, US
Jeffrey Bryant Price - Sunnyvale CA, US

Assignee:

Finisar Corporation - Sunnyvale CA

International Classification:

H04B 10/06

US Classification:

398202, 250214 R, 250214 SW

Abstract:

A controller for controlling the reverse-bias voltage of an avalanche photodiode in a transceiver or receiver. The controller includes memory for storing information related to the avalanche photodiode, and analog to digital conversion circuitry for receiving an analog signal corresponding to the temperature of the avalanche photodiode, converting the received analog signal into a digital value, and storing the digital value in a predefined location within the memory. Control circuitry in the controller controls the operation of the avalanche photodiode and a temperature lookup table store in the memory. A serial interface enables a host device to read from and write to locations within the memory. The invention also controls the reverse-bias voltage of an avalanche photodiode in a transceiver or receiver.

US Patent:

7217914, May 15, 2007

Filed:

Jul 27, 2004

Appl. No.:

10/899904

Inventors:

James Stewart - San Jose CA, US
Anthony Ho - Sunnyvale CA, US
Rudolf J. Hofmeister - Sunnyvale CA, US
Darin James Douma - Monrovia CA, US
Lucy G. Hosking - Santa Cruz CA, US
Andreas Weber - Los Altos CA, US
Jeffrey Bryant Price - Sunnyvale CA, US

Assignee:

Finisar Corporation - Sunnyvale CA

International Classification:

H01J 40/14
H01L 35/00
H02H 5/04

US Classification:

250214R, 327513, 361 938

Abstract:

Methods and processes are disclosed for calibrating optoelectronic devices, such as optoelectronic transceivers and optoelectronic receivers, based upon an avalanche photodiode breakdown voltage. In general, the method involves adjusting a reverse-bias voltage of the avalanche photodiode until avalanche breakdown of the avalanche photodiode occurs. An optimized APD reverse-bias voltage is then determined by reducing the reverse-bias voltage at which avalanche breakdown occurs by a predetermined offset voltage. This process is performed at a variety of different temperatures. Information concerning each temperature and the corresponding optimized APD reverse-bias voltage is stored in a memory of the optoelectronic device.

US Patent:

7369587, May 6, 2008

Filed:

Dec 21, 2004

Appl. No.:

11/020052

Inventors:

James Stewart - Burlingame CA, US
Anthony Ho - Sunnyvale CA, US

International Classification:

H01S 3/13

US Classification:

372 2902, 372 3802, 372 29015

Abstract:

Optoelectronic devices and methods are used to maintain a CWDM transmitter operating within design parameters over an extended ambient temperature range. In order to avoid excessive wavelength drift with temperature shifts, lasers in the CWDM transmitters are heated or cooled to a selected temperature, for example by using a thermoelectric cooler. By heating and cooling the lasers, any wavelength drift that an ambient temperature variation might inflict on the laser is minimized to the range hotter or colder than the selected temperature. As the temperature range of the laser increases above the selected temperature, the AC swing driving the laser is increased to maintain a sufficient extinction ratio for acceptable transmitter performance.