Ming Li

US Patent:

6529307, Mar 4, 2003

Filed:

Jun 4, 2001

Appl. No.:

09/874474

Inventors:

Song Peng - Pleasanton CA
Ming Li - Pleasanton CA

Assignee:

Avanex Corporation - Fremont CA

International Classification:

G02F 103

US Classification:

359256, 359315, 359319, 359245, 359250

Abstract:

A method and apparatus for achieving dynamic intensity modulation of the channels in a wavelength-division multiplexed optical communication system is presented. Wavelengths are spatially separated into a plurality of channels, the polarization states of which are individually modulated. The channels can be combined or filtered by polarization states to achieve the desired intensity in the output signal. An exemplary embodiment includes at least a polarization modulator, a birefringent wedge, a lens, and a dispersive element (e. g. , diffraction grating) arranged in various order. Each segment of the polarization modulator can be made to rotate the polarization direction of an incident channel by a specified angle. A half-wave plate may be inserted between the second dispersive element and the second birefringent wedge to eliminate polarization-dependent loss. Optionally, a parallel birefringent plate may be inserted after the second birefringent wedge to reduce polarization mode dispersion.

US Patent:

6546159, Apr 8, 2003

Filed:

Aug 22, 2002

Appl. No.:

10/225650

Inventors:

Song Peng - Pleasanton CA
Ming Li - Pleasanton CA

Assignee:

Avanex Corporation - Fremont CA

International Classification:

G02B 600

US Classification:

385 11, 356399, 2502014, 349 77

Abstract:

An improved digital differential group delay (DGD) controller is capable of producing variable DGD used to compensate for DGD in a fiber optic link in real time. The DGD controller comprises one or more sets of a polarization modulator optically coupled with a fixed delay component, such as a birefringent plate. Each set provides an amount of DGD compensation. By controlling the number of stages in the controller, the amount of DGD compensation provided by each stage, and which stages are placed in the ON state, the total amount of DGD compensation provided by the digital DGD controller can be varied.

US Patent:

6594082, Jul 15, 2003

Filed:

Feb 26, 2001

Appl. No.:

09/794590

Inventors:

Ming Li - Pleasanton CA
Song Peng - Fremont CA

Assignee:

Avanex Corporation - Fremont CA

International Classification:

G02B 2600

US Classification:

359618, 359290, 385 11

Abstract:

An optical wavelength router utilizes a dispersive medium (e. g. , a diffraction grating) and reflective surfaces. The dispersive medium separates an input optical signal (light beam) into a plurality of components, for example by wavelengths. The reflective surfaces convert the components into separate output beams traveling in the desired directions. The number and the direction of the output beams can be controlled by manipulating the angle of incidence at which the components strike the reflective surfaces. A micro-mirror array modulator serves as the reflective surfaces. Each mirror in the micro-mirror array modulator is positioned to direct individual components into a number of output signals. Alternatively, a polarization steering device which includes a polarization modulator and at least one birefringent element in addition to reflective surfaces is utilized. A Wollaston prism with a reflective surface may also be used.

US Patent:

6728488, Apr 27, 2004

Filed:

Jan 23, 2002

Appl. No.:

10/056452

Inventors:

Song “Sean” Peng - Pleasanton CA
Ming “Miles” Li - Pleasanton CA

Assignee:

Avanex Corporation - Fremont CA

International Classification:

H04J 1402

US Classification:

398 86, 358 87, 359639, 359640

Abstract:

An optical device includes: a collimator; at least one anamorphic pair of prisms optically coupled to the collimator; a diffraction grating optically coupled to the at least one anamorphic pair of prisms at a side opposite to the collimator; and a focusing lens optically coupled to the diffraction grating. The anamorphic pair of prisms permits light incident upon the diffraction grating to be relatively narrow in a dimension perpendicular to the dispersive direction of the grating so that the grating can produce high spectral resolution while preserving compact system size and simplicity.

US Patent:

6947628, Sep 20, 2005

Filed:

Aug 28, 2002

Appl. No.:

10/231407

Inventors:

Song Peng - Pleasanton CA, US
Ming Li - Pleasanton CA, US

Assignee:

Avanex Corporation - Fremont CA

International Classification:

G02B006/26

US Classification:

385 18, 385 16, 385 15

Abstract:

A wavelength-selective optical add-drop switch includes a first and a second 1×2 wavelength switch optically coupled to one another via at least one mirror. Each of the first and second 1×2 wavelength switches has a switch input and two switch outputs, a wavelength dispersive medium optically coupled to the switch input and the two switch outputs, a lens optically coupled to the wavelength dispersive medium and a segmented beam steering apparatus optically coupled to the lens opposite to the wavelength dispersive medium. The add-drop wavelength switch has a high extinction ratio and low loss.

US Patent:

7073952, Jul 11, 2006

Filed:

Jun 5, 2002

Appl. No.:

10/163405

Inventors:

Frank Xi Wu - Fremont CA, US
Jian Xu - Pleasanton CA, US
Ming Li - Pleasanton CA, US
Song Peng - Pleasanton CA, US

Assignee:

Avanex Corporation - Fremont CA

International Classification:

G02B 6/26
G02B 7/00

US Classification:

385 62, 385 90, 385 28, 359896, 24828831

Abstract:

An optical alignment device holds fiber collimators in place with extremely good mechanical and environmental stability. The device includes a ball with a hole traversing the ball, an upper clamping block with a first inner concave spherical surface and a lower clamping block with a second inner concave spherical surface. The hole includes a shape that can accommodate or contact an optical component whose alignment is to be controlled. The ball, together with the enclosed optical component is firmly held between the first and second inner concave surfaces of the clamping blocks, which are tightened against the ball with screws. When firmly clamped within the concave surfaces, the ball is prevented from accidental movement but can still rotate about any axis to align the optical component. Once alignment is achieved, the optical component and the ball are secured in place by epoxy, glue, solder or other suitable adhesive.

US Patent:

7245328, Jul 17, 2007

Filed:

Jun 17, 2002

Appl. No.:

10/173290

Inventors:

Haijun Yuan - Pleasanton CA, US
Ming Li - Pleasanton CA, US
Song Peng - Pleasanton CA, US

Assignee:

Avanex Corporation - Fremont CA

International Classification:

G02F 1/133

US Classification:

349 33, 349 72, 349 34

Abstract:

A polarization controller includes: a liquid crystal cell; a mechanism for determining a compensation voltage; and a voltage driving circuit for applying the compensation voltage to the liquid crystal cell, where the application of the compensation voltage optimizes an extinction ratio of the liquid crystal cell. The controller controls the extinction ratio using an applied voltage to compensate for temperature changes, liquid crystal cell gap variations, and other errors of the liquid crystal cell. This controller is aimed at liquid crystal devices used in a wide ambient temperature range and is also useful to compensate for the fabrication errors of the liquid crystal switches.

US Patent:

7298540, Nov 20, 2007

Filed:

Aug 22, 2002

Appl. No.:

10/225936

Inventors:

Song Peng - Pleasanton CA, US
Ming Li - Pleasanton CA, US

Assignee:

Avanex Corporation - Fremont CA

International Classification:

G02F 1/01
G02B 5/30
G02B 5/18
H04J 14/02
H04J 14/06

US Classification:

359256, 359316, 359485, 359566, 359250, 398 49, 398 65, 398 87

Abstract:

A dynamic equalizing optical channel router includes an input port for receiving a wavelength division multiplexed composite optical signal comprising a plurality of channels; at least one output port; a diffraction grating optically coupled to the input and output ports; a lens optically coupled to the diffraction grating at a side opposite to the input and output ports; an array of steering devices optically coupled to the lens at a side opposite to the diffraction grating, wherein each channel is reflected by a different steering device of the array; and a plurality of attenuators, wherein each channel reflected by the array traverses one of the attenuators and the diffraction grating to the at least one output port. The router is able to dynamically adjust optical intensity of each wavelength channel by a different amount while also performing the function of wavelength routing.