Steven Thai Nguyen

US Patent:

8269297, Sep 18, 2012

Filed:

Dec 23, 2009

Appl. No.:

12/646558

Inventors:

Radhakrishnan L. Nagarajan - Cupertino CA, US
Andrew G. Dentai - Mountain View CA, US
Scott Corzine - Sunnyvale CA, US
Steven Nguyen - San Jose CA, US
Vikrant Lal - Sunnyvale CA, US
Jacco L. Pleumeekers - Mountain View CA, US
Peter W. Evans - Mountain House CA, US

Assignee:

Infinera Corporation - Sunnyvale CA

International Classification:

H01L 31/0232

US Classification:

257432, 257189, 257E31056

Abstract:

Consistent with the present disclosure, a current blocking layer is provided between output waveguides carrying light to be sensed by the photodiodes in a balanced photodetector, and the photodiodes themselves. Preferably, the photodiodes are provided above the waveguides and sense light through evanescently coupling with the waveguides. In addition, the current blocking layer may include alternating p and n-type conductivity layers, such that, between adjacent ones of such layers, a reverse biased pn-junction is formed. The pn-junctions, therefore, limit the amount of current flowing from one photodiode of the balanced detector to the other, thereby improving performance.

US Patent:

20140111114, Apr 24, 2014

Filed:

Dec 23, 2013

Appl. No.:

14/139725

Inventors:

- NEWPORT BEACH CA, US
Fabio Gozzini - Campbell CA, US
Steven Van Nguyen - Garden Grove CA, US

Assignee:

MINDSPEED TECHNOLOGIES, INC. - NEWPORT BEACH CA

International Classification:

H05B 37/02

US Classification:

315297

Abstract:

A system is disclosed to automatically establish proper biasing for light sources in a color mixed projection system having multiple light sources which are active at the same time. Responsive to a feedback signal, a single DC-DC converter generates the bias voltage for the light sources. Comparators compare a headroom signal for each light source to a reference value to generate comparator output signals. The comparator output signals are processed by a channel selector and a digital filter/DAC module. The channel selector controls a switch to selectively provide and combine a headroom signal with an output of the digital filter/DAC module to create the feedback signal. By monitoring each headroom value, the bias voltage is adjusted, based on the feedback signal, until every headroom signal reaches the reference value thereby achieving sufficient biasing for every active light source in the color mixed projection system.