Reconfigurable modulator-based optical add-and-drop multiplexer

• US 7,286,764 B1
• Filed: 02/03/2003
• Issued: 10/23/2007
• Est. Priority Date: 02/03/2003
• Status: Active Grant

• Current Assignee: Silicon Light Machines Corporation (SCREEN Holdings Co., Ltd.)
• Original Assignee: Silicon Light Machines Corporation (SCREEN Holdings Co., Ltd.)
• Inventors: Carlisle, Clinton B., Trisnadi, Jahja I.
• Primary Examiner(s): Chan; Jason
• Assistant Examiner(s): Leung; Wai Lun
• Application Number:
  US10/357,620
• Time in Patent Office: 1,723 Days
• Field of Search: 398/50, 398/87, 398/84, 369/103, 385/10, 359/558, 359/572
• US Class Current: 398/84
• CPC Class Codes: G02B 6/2931 Diffractive element operating in reflection
• CPC Class Codes: G02B 6/29313 characterised by means for controlling the position or direction of light incident to or leaving the diffractive element, e.g. for varying the wavelength response switching G02B6/35
• CPC Class Codes: G02B 6/29383 Adding and dropping
• CPC Class Codes: G02B 6/29395 configurable, e.g. tunable or reconfigurable switching G02B6/35
• CPC Class Codes: G02B 6/3516 the reflective optical element moving along the beam path, e.g. controllable diffractive effects using multiple micromirrors within the beam
• CPC Class Codes: G02B 6/357 Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841
• CPC Class Codes: H04J 14/0201 Add-and-drop multiplexing

Abstract

An optical add and drop multiplexer system comprising a first module for providing a first signal; a second module for providing a second signal; and a modulator for receiving a channel of the first signal at a first location, the first location configured to actuate between a first configuration and a second configuration, wherein the modulator directs the channel of the first signal as an output signal when the first location is in the first configuration. The modulator may direct the channel of the first signal as a dropped signal when the first location is in the second configuration. The modulator may also receive a channel of the second signal from the second module at a second location configured to independently actuate between the first configuration and the second configuration.

Claims

1. An optical add and drop multiplexer system comprising:

a. a first module for providing a first input signal and receiving a first output signal;

b. a second module for providing a second input signal and receiving a second output signal;

c. a fixed diffraction grating configured to produce a first set of component signals from the first input signal and a second set of component signals from the second input signal;

d. a mirror configured to reflect the second input signal from the second module to the diffraction grating and to reflect component signals to be received by the second module from the diffraction grating to the second module; and

e. a modulator using controllable diffraction for receiving the first and second sets of component signals, wherein corresponding component signals in the first and second sets are received at a same location on the modulator, each said location being configured to actuate between a first configuration and a second configuration,

wherein each said location reflects a component signal of the first set to the first module and a corresponding component signal of the second set to the second module when a location is in the first configuration, and diffracts the component signal of the first set to the second module and the corresponding component signal of the second set to the first module when the location is in the second configuration, and

further wherein one of the first and second configurations comprises a plurality of reflective surfaces being in a first plane, and another of the first and second configurations comprises every other one of the plurality of reflective surfaces being in the first plane and a remainder of the plurality of the reflective surfaces being in a second plane.

2. The system according to claim 1 wherein the first module comprises:

a. a circulator configured to receive the first input signal at a first port, to transmit the first input signal from and receive the first output signal at a second port, to transmit the first output signal from a third port; and

b. a polarization-diversity optical module (PDM) for directing the first input and output signals between the circulator and the diffraction grating.

3. The system according to claim 1 wherein the second module comprises:

a. a circulator configured to receive the second input signal at a first port, to transmit the second input signal from and receive the second output signal at a second port, to transmit the second output signal from a third port;

b. a polarization-diversity optical module (PDM) for directing the second input and output signals between the circulator and the diffraction grating.

4. The system according to claim 1 wherein the modulator is a grating light valve.

5. The system according to claim 1 further comprising a multiplexing module for dynamically equalizing the output signal, wherein the multiplexing module is coupled to the second module.

6. The system according to claim 1 wherein the fixed diffraction grating is a blazed diffraction grating.

7. An apparatus for modulating a first wavelength division multiplexed (WDM) signal with a second WDM signal, the apparatus comprising:

a. a first module for providing the first WDM signal;

b. a second module for providing the second WDM signal;

c. a fixed diffraction grating configured to separate the first set of component signals of the first WDM signal and to separate a second set component signals of the second WDM signal; and

d. a grating light valve array for receiving the first and second sets of component signals, wherein corresponding component signals of the first and second sets are received at a same grating light valve device of the array, each said grating light valve device being configurable into a first configuration and a second configuration,

wherein each said grating light valve device reflects a component signal of the first set to the first module and a corresponding component signal of the second set to the second module when in the first configuration, and diffracts the component signal of the first set to the second module and the corresponding component signal of the second set to the first module when in the second configuration, and

wherein one of the first and second configurations comprises a plurality of reflective surfaces being in a first plane, and another of the first and second configurations comprises alternate ones of the plurality of reflective surfaces being in the first plane and remaining ones of the plurality of reflective surfaces being in a second plane.

8. The apparatus according to claim 7 wherein the fixed diffraction grating is a blazed diffraction grating.

9. An apparatus for modulating a first signal and a second signal, the apparatus comprising:

a. means for inputting the first signal, wherein the first signal includes a first group of component signals;

b. means for inputting a second signal, wherein the second signal includes a second group of component signals;

c. a fixed diffraction means configured to produce a first plurality of component signals from the first signal and a second plurality of component signals from the second signal; and

d. means using controllable diffraction for modulating the first signal and second signal,

wherein the means for modulating receives the first and second pluralities of component signals at a predetermined plurality of locations,

further wherein the means for modulating selects a component signal from either the first plurality or the second plurality at each said location depending upon a device configuration,

further wherein said device configuration is selected to be either a first or second configuration, the first configuration comprising a plurality of reflective surfaces lying in a first plane, and the second configuration comprising the plurality of reflective surfaces being either in the first plane and in a second plane in an alternating manner.