John J Stronczer

US Patent:

6825964, Nov 30, 2004

Filed:

Oct 22, 2002

Appl. No.:

10/277290

Inventors:

Prashant Singh - Eden Prairie MN
Helga Foulk - Ambler PA
Scott Redinger - Breinigsville PA
Todd Tanji - Eagan MN
Keith Maile - New Brighton MN
John Stronczer - Minneapolis MN

Assignee:

T-Networks, Inc. - Allentown PA
AMCC - San Diego CA

International Classification:

G02F 103

US Classification:

359248, 372 43, 385 2

Abstract:

Drive circuitry to provide a DC bias voltage and a high frequency modulation current to an electroabsorption modulator (EAM), including a high frequency modulation current source, a coupling capacitor, and a first DC lead. The drive circuitry may include termination circuitry. One lead of the high frequency modulation current source is electrically coupled to the first semiconductor type contact of the EAM and the other lead of the high frequency modulation current source is electrically coupled to an AC ground. The coupling capacitor includes a first electrode electrically coupled to the second semiconductor type contact of the EAM, a second electrode electrically coupled to the AC ground, and a dielectric layer between the electrodes. The first DC lead is electrically coupled to the EAM-side capacitor electrode and configured to be coupled to a first DC potential.

US Patent:

6836350, Dec 28, 2004

Filed:

Mar 5, 2004

Appl. No.:

10/793971

Inventors:

Prashant Singh - Eden Prairie MN
Helga Foulk - Ambler PA
Scott Redinger - Breinigsville PA
Todd Tanji - Eagan MN
Keith Maile - New Brighton MN
John Stronczer - Minneapolis MN

Assignee:

T-Networks, Inc. - Allentown PA
AMCC - San Diego CA

International Classification:

G02F 101

US Classification:

359240, 359245, 359246, 359248, 438718

Abstract:

Drive circuitry to provide a DC bias voltage and a high frequency modulation current to an electroabsorption modulator (EAM), including a high frequency modulation current source, a coupling capacitor, and a first DC lead. The drive circuitry may include termination circuitry. One lead of the high frequency modulation current source is electrically coupled to the first semiconductor type contact of the EAM and the other lead of the high frequency modulation current source is electrically coupled to an AC ground. The coupling capacitor includes a first electrode electrically coupled to the second semiconductor type contact of the EAM, a second electrode electrically coupled to the AC ground, and a dielectric layer between the electrodes. The first DC lead is electrically coupled to the EAM-side capacitor electrode and configured to be coupled to a first DC potential.

US Patent:

6879608, Apr 12, 2005

Filed:

Mar 31, 2003

Appl. No.:

10/404908

Inventors:

Robert John Schuelke - Lakeville MN, US
John J. Stronczer - Minneapolis MN, US

Assignee:

Applied Micro Circuits Corporation - San Diego CA

International Classification:

H01S003/00

US Classification:

372 3802, 372 3807

Abstract:

A laser driver includes two DC-coupled differential drive circuits in which the common mode voltage of the first differential drive circuit is maintained a level affording a high compliance voltage for a laser diode driven by the second differential drive circuit. This is accomplished by means of an operational amplifier which compares the common mode voltage of the second differential drive circuit to a reference voltage. The operational amplifier operates in a closed-loop configuration to draw current through a common mode bias resistor in the first differential drive circuit in order to force the common mode voltage of the second differential drive circuit to a desired value determined by the reference voltage.