Daniel M Case

US Patent:

6728276, Apr 27, 2004

Filed:

Oct 30, 2002

Appl. No.:

10/285203

Inventors:

Philip D. Shapiro - Palo Alto CA
Daniel K. Case - Gilroy CA

Assignee:

Finisar Corporation - Sunnyvale CA

International Classification:

H01S 300

US Classification:

372 3802, 372 3803

Abstract:

The present invention relates generally to laser diodes, and particularly to an operational amplifier able to switch laser diodes on and off quickly without adversely affecting data transmission by the laser diodes. A differential amplifier included in an operational amplifier has a high transconductance when a laser diode is first turned on and a low, near constant transconductance when the laser diode is transmitting data. The operational amplifier is preferably incorporated in optoelectronic transceivers used in passive optical networks. Switching laser diodes on and off quickly enables more efficient use of network bandwidth in such passive optical networks.

US Patent:

6778021, Aug 17, 2004

Filed:

Dec 11, 2003

Appl. No.:

10/733681

Inventors:

Gilles P. Denoyer - San Jose CA
Daniel Case - Gilroy CA

Assignee:

Finisar Corporation - Sunnyvale CA

International Classification:

H03F 308

US Classification:

330308, 330110, 250214 A

Abstract:

A wide dynamic range transimpedance amplifier with a low cut off frequency at high optical power. An automatic transimpedance gain control and DC cancellation control feedback circuit includes variable impedance circuitry. An emitter terminal of a first pnp transistor is connected to the input of the transimpedance amplifier. The impedance seen at the emitter terminal changes according to the average value of the input current. Open loop gain of the feedback loop including the first pnp transistor is not dependent on the average input current as the input current increases. A base terminal of the first pnp transistor is connected to a base terminal of second pnp transistor. Emitter size of the second pnp transistor is some factor N smaller than emitter size of the first pnp transistor. N can be configured to adjust the gain control and low corner frequency variation with input power.

US Patent:

6841815, Jan 11, 2005

Filed:

Oct 30, 2002

Appl. No.:

10/285204

Inventors:

Daniel K. Case - Gilroy CA, US
Philip D. Shapiro - Palo Alto CA, US

Assignee:

Finisar Corporation - Sunnyvale CA

International Classification:

H05K 111
H01L 2976

US Classification:

257293, 257292, 257528, 361173

Abstract:

The optoelectronic device includes a photo diode and an amplifier, which amplifies output of the photo diode. The amplifier includes an input stage and an output stage. In one embodiment, the input stage has a series connection to a resistor, which is connected to a ground. The output stage has a connection to ground that does not overlap the series connection. In another embodiment, the input stage has a first connection to a bypass capacitor, which is connected to a power source. The output stage has a separate, second connection to the capacitor, which prevents high frequencies from flowing between the input stage and said output stage via a connection to the power source.

US Patent:

6847263, Jan 25, 2005

Filed:

May 5, 2004

Appl. No.:

10/839640

Inventors:

Gilles P. Denoyer - San Jose CA, US
Daniel Case - Gilroy CA, US

Assignee:

Finisar Corporation - Sunnyvale CA

International Classification:

H03F 308
H03F 136
H01J 4014

US Classification:

330308, 330110, 250214 A

Abstract:

An optical component is provided that includes a detector configured to transmit an input current to a transimpedance amplifier that includes an automatic transimpedance gain control and DC cancellation control feedback circuit having variable impedance circuitry. Open loop gain of the feedback circuit is independent of the average input current as the input current increases. The feedback circuit includes first and second pnp transistors arranged so that their respective bases are connected and so that an emitter terminal of the first pnp transistor is connected to the input of the transimpedance amplifier, and the impedance seen at the emitter terminal changes according to the average value of the input current. The emitter size of the second pnp transistor is a factor N smaller than emitter size of the first pnp transistor. N can be selected to adjust the gain control and low corner frequency variation with input power.

US Patent:

6876004, Apr 5, 2005

Filed:

Dec 4, 2001

Appl. No.:

10/005924

Inventors:

Paul K. Rosenberg - Sunnyvale CA, US
Daniel K. Case - Gilroy CA, US
Jan Lipson - Cupertino CA, US
Rudolf J. Hofmeister - Sunnyvale CA, US

Assignee:

Finisar Corporation - Sunnyvale CA

International Classification:

H01L029/267
G02B006/36
G02F001/29

US Classification:

257 81, 257 83, 257 98, 257 99, 257433, 385 89, 385 92, 385 94, 359316

Abstract:

An optoelectronic assembly includes a transistor outline (TO) package that houses an optoelectronic device. The TO package and the optoelectronic device are coupled to a circuit interconnect. The circuit interconnect includes an insulator having a first side for transmitting a signal current between the optoelectronic device and a device external to the TO package, and a second side for transmitting a ground current between the TO package and the external device. For a predefined operating frequency range, the impedance of the circuit interconnect approximately matches the impedance of the signal leads of the TO package and also approximately matches the impedance of the device external to the TO package. The optoelectronic device may include a laser diode or a photo diode. In addition, the present invention is an optoelectronic transceiver including a transmitter optoelectronic assembly and a receiver optoelectronic assembly.

US Patent:

6999011, Feb 14, 2006

Filed:

Mar 31, 2004

Appl. No.:

10/814440

Inventors:

Daniel Case - Gilroy CA, US
Gerald L. Dybsetter - Scotts Valley CA, US
Jayne C. Hahin - Cupertino CA, US

Assignee:

Finisar Corporation - Sunnyvale CA

International Classification:

H03M 1/06

US Classification:

341118, 341155, 341161

Abstract:

Microcode driven adjustment of analog scaling of an analog signal prior to being provided to an analog-to-digital converter. The microcode also causes the system to read the resulting digital value, and determine whether the scaling value should be adjusted for that analog signal. Accordingly, the microcode may cause the analog signal to be dynamically adjusted to be within the input range of the analog-to-digital converter, thereby allowing for more accurate digital conversions with lower resolution analog-to-digital converters. The microcode rapidly adjusts for any fluctuations in the input voltage. Accordingly, the analog signal may fluctuate, or even be multiplexed from a wide variety of different analog signal sources.

US Patent:

7020170, Mar 28, 2006

Filed:

Nov 25, 2003

Appl. No.:

10/722087

Inventors:

Philip D. Shapiro - Palo Alto CA, US
Daniel K. Case - Gilroy CA, US

Assignee:

Finisar Corporation - Sunnyvale CA

International Classification:

H01S 3/00

US Classification:

372 3802, 372 3803

Abstract:

An optoelectronic transceiver is provided that includes a laser driver in communication with an optical transmitter. The laser driver includes an operational amplifier having three stages and connected with an optical transmitter. The first stage includes a differential amplifier that receives a reference voltage input, corresponding to a desired magnitude of the optical transmitter voltage, and an optical transmitter voltage input, representing an optical output strength of the optical transmitter, and having transconductance that increases exponentially as a difference between the reference voltage and the optical transmitter voltage increases. The differential amplifier generates an output current based on the inputs. The second stage integrates the output current to generate a first output voltage. Finally, the third stage is configured to receive as input the first output voltage to generate a second output voltage approximately equal to the first output voltage, the second output voltage controlling an optical transmitter bias current.

US Patent:

7211830, May 1, 2007

Filed:

Jan 6, 2005

Appl. No.:

11/030412

Inventors:

Paul K. Rosenberg - Sunnyvale CA, US
Daniel K. Case - Gilroy CA, US
Jan Lipson - Cupertino CA, US
Rudolf J. Hofmeister - Sunnyvale CA, US

Assignee:

Finisar Corporation - Sunnyvale CA

International Classification:

H01L 29/267
G02B 6/36
G02F 1/29

US Classification:

257 81, 257 83, 257 98, 257 99, 257433, 385 89, 385 92, 385 94, 359316

Abstract:

This disclosure concerns systems and devices configured to implement impedance matching schemes in a high speed data transmission environment. In one example, an optoelectronic assembly is provided that includes a TO package having a base through which one or more leads pass. The leads are electrically coupled to an optoelectronic device in the TO package, and are electrically isolated from the base. Some or all of the leads include a ground ring that is electrically isolated from the lead and electrically coupled with the base. A circuit interconnect is also included that is electrically coupled to the optoelectronic device and the TO package. The circuit interconnect includes a dielectric substrate having signal traces that are electrically coupled to the signal leads. A ground signal conductor disposed on the dielectric substrate is electrically coupled with the ground rings.