John Jih Jong Feng

US Patent:

7340130, Mar 4, 2008

Filed:

Oct 11, 2005

Appl. No.:

11/247779

Inventors:

Xuehua Wu - Union City CA, US
Mingjun Zhao - Fremont CA, US
John Feng - Union City CA, US

Assignee:

Avanex Corporation - Fremont CA

International Classification:

G02B 6/34

US Classification:

385 34, 385 33, 385 84

Abstract:

The present invention describes a structure and method for a multi-ports WDM device for compensating the filter distortion while reducing insertion loss. The multi-ports WDM device comprises a 4-fiber collimator having a grin lens and a 2-fiber collimator having a lens where the focal plane of the second lens is shorter than the focal plane of the first grin lens Ands with aspheric surface. When a light signal travels through the first lens in the 4-fiber collimator to a filter, the film on the filter causes distortion to the light signal resulting in a large insertion loss. To compensate for the insertion loss, the lens on the 2-fiber collimator has a aspheric function and a shorter focal plane than the grin lens on the 4-fiber collimator. The type of grin lens used in the 4-fiber collimator is different than the lens used in the 2-fiber collimator. Effectively, the lens in the 2-fiber collimator operates to de-focus a light signal relative to the grin lens in the 4-fiber collimator.

US Patent:

7454143, Nov 18, 2008

Filed:

Dec 15, 2003

Appl. No.:

10/736818

Inventors:

Xuehua Wu - Union City CA, US
Mingjun Zhao - Fremont CA, US
John Feng - Union City CA, US
Giovanni Barbarossa - Saratoga CA, US

Assignee:

Avanex Corporation - Fremont CA

International Classification:

H04J 14/02

US Classification:

398 85

Abstract:

A reconfigurable thin film based dense wavelength division multiplexing (DWDM) device is described for hitless switching of wavelengths by employing a reconfigurable filtering device. The reconfigurable filtering device is based on a mechanical switching of a filtering chip which has a thin film coated a first one-half of a first face for interference wavelength filtering and has a gold-mirror coated on a second one-half of the first face for high reflection.

US Patent:

7457544, Nov 25, 2008

Filed:

Nov 16, 2004

Appl. No.:

10/990688

Inventors:

John Feng - Union City CA, US
Xuehua Wu - Union City CA, US
Sanjai Parthasarathi - Los Altos CA, US

Assignee:

Avanex Corporation - Fremont CA

International Classification:

H04J 14/02

US Classification:

398 85, 398 79, 398 82, 398 83, 398 84, 398 87, 398102, 398161, 398159, 398180, 398158, 385 24, 385 37, 385 14, 385 27, 385 33, 385 34, 385 31

Abstract:

A group delay compensation equalizer is disclosed that employs a single channel four-port WDM device for compensating the group delay experienced by a plurality of wavelengths transmitted over different paths. The transmission differential between two wavelengths is compensated by transmitting the two wavelengths through two different paths where the fiber length in reflecting the second wavelength is equal to the transmission time difference between the two wavelengths. The single channel four-port group delay equalizer effectively provides a unidirectional signal flow, as compared to the conventional equalizer that transmits optical signals bi-directionally. The present invention reduces the cost of a group delay equalizer by simplifying the use of multiple three-port WDM devices into a single channel four-port WDM device. The present invention further reduces the number of alignments required to just one on the transmission side since the group delay equalizer now has one transmission output, rather than two transmission outputs in a prior solution.

US Patent:

7171073, Jan 30, 2007

Filed:

Oct 11, 2005

Appl. No.:

11/247052

Inventors:

Xuehua Wu - Union City CA, US
Mingjun Zhao - Fremont CA, US
John Feng - Union City CA, US

Assignee:

Avanex Corporation - Fremont CA

International Classification:

G02B 6/293
G02B 6/32
H04J 14/02

US Classification:

385 24, 385 34, 398 85, 398 88

Abstract:

The present invention describes a structure and method for a multi-ports WDM device for compensating the filter distortion while reducing insertion loss. The multi-ports WDM device comprises a 4-fiber collimator having a grin lens and a 2-fiber collimator having a lens where the focal plane of the second lens is shorter than the focal plane of the first grin lens Ands with aspheric surface. When a light signal travels through the first lens in the 4-fiber collimator to a filter, the film on the filter causes distortion to the light signal resulting in a large insertion loss. To compensate for the insertion loss, the lens on the 2-fiber collimator has a aspheric function and a shorter focal plane than the grin lens on the 4-fiber collimator. The type of grin lens used in the 4-fiber collimator is different than the lens used in the 2-fiber collimator. Effectively, the lens in the 2-fiber collimator operates to de-focus a light signal relative to the grin lens in the 4-fiber collimator.