Monolithic reconfigurable optical multiplexer systems and methods

• US 20040114856A1
• Filed: 11/25/2003
• Published: 06/17/2004
• Est. Priority Date: 11/08/2001
• Status: Active Grant

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Su, Yi, Kubby, Joel A., Lin, Pinyen, Chen, Jingkuang
• Granted Patent: US 6,990,265 B2
• Time in Patent Office: Days
• US Class Current: 385/16
• CPC Class Codes: G02B 2006/12061 Silicon
• CPC Class Codes: G02B 2006/12097 Ridge, rib or the like
• CPC Class Codes: G02B 2006/12107 Grating
• CPC Class Codes: G02B 2006/12145 Switch
• CPC Class Codes: G02B 2006/12164 Multiplexing; Demultiplexing
• CPC Class Codes: G02B 6/12021 Comprising cascaded AWG devices; AWG multipass configuration; Plural AWG devices integrated on a single chip
• CPC Class Codes: G02B 6/12033 characterised by means for configuring the device, e.g. moveable element for wavelength tuning switching G02B6/35; thermo-optic devices G02F1/0147
• CPC Class Codes: G02B 6/2938 for multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM
• CPC Class Codes: G02B 6/3508 Lateral or transverse displacement of the whole waveguides, e.g. by varying the distance between opposed waveguide ends, or by mutual lateral displacement of opposed waveguide ends
• CPC Class Codes: G02B 6/3512 the optical element being reflective, e.g. mirror
• CPC Class Codes: G02B 6/356 in an optical cross-connect device, e.g. routing and switching aspects of interconnecting different paths propagating different wavelengths to (re)configure the various input and output links switching polarized beams G02B6/3594; power equalizers G02B6/356 and G02B6/3594; path selecting means H04Q11/0001
• CPC Class Codes: G02B 6/3584 constructional details of an associated actuator having a MEMS construction, i.e. constructed using semiconductor technology such as etching MEMS per se B81B, B81C
• CPC Class Codes: G02B 6/3596 With planar waveguide arrangement, i.e. in a substrate, regardless if actuating mechanism is outside the substrate

Abstract

A silicon demultiplexer, a plurality of silicon switches and a silicon multiplexer are monolithicaily integrated on a single silicon chip. In embodiments, the silicon demultiplexer and the silicon multiplexer each comprise a diffraction grating. In other embodiments, the silicon demultiplexer and the silicon multiplexer each comprise an arrayed waveguide grating. In various exemplary embodiments, the silicon optical switches comprise optical switches, micromachined torsion mirrors, electrostatic micromirrors, and/or tilting micromirrors. In use, an optical signal comprising a multiplexed data stream is input into the monolithic reconfigurable optical multiplexer. An optical signal that comprises a modified multiplexed data stream may be output. In an optical communications system, the silicon demultiplexer communicates with an input optical fiber, the plurality of silicon optical switches communicate between the silicon demultiplexer and the silicon multiplexer, and the silicon multiplexer communicates with an output optical fiber. In various embodiments, the optical switches are fabricated to be self-aligned.

Claims

1. A micro-optical device having an aligned waveguide switch, comprising:

a stationary input part with a plurality of input waveguides;

a stationary output part with a plurality of output waveguides;

a movable part with a plurality of switching waveguides, the movable part being movable relative to the stationary input and output parts; and

at least one stop block that limits movement of the movable part to align at least one of the switching waveguides with at least one of the input waveguides and at least one of the output waveguides.

2. The device of claim 1, wherein the stationary input part, the stationary output part and the movable part comprise a single-crystal-silicon layer of the device.

3. The device of claim 2, wherein the at least one stop block comprises a stationary part of the single-crystal-silicon layer.

4. The device of claim 2, wherein the at least one stop block comprises a polysilicon layer of the device.

5. The device of claim 4, further comprising at least one polysilicon bumper connected to the movable part.

6. The device of claim 1, wherein the at least one stop block comprises a polysilicon layer of the device.

7. The device of claim 6, further comprising at least one polysilicon bumper connected to the movable part.

8. A method for fabricating a micro-optical device having an aligned waveguide switch, comprising:

forming a stationary input part, a stationary output part and a movable part in a structural layer;

forming a plurality of waveguides in the stationary input part, the stationary output part and the movable part; and

forming at least one stop block that limits movement of the movable part to align at least one of the waveguides of the movable part with at least one of the waveguides of the stationary input and output parts.

9. The method of claim 8, wherein forming the plurality of waveguides comprises defining a set of offsets between the waveguides of the movable part and the waveguides of the stationary input and output parts, and

wherein forming the at least one stop block comprises defining the at least one stop block with the set of offsets.

10. The method of claim 9, wherein forming the at least one stop block further comprises defining at least one edge of the movable part with the set of offsets.

11. The method of claim 9, wherein forming the at least one stop block further comprises defining at least one bumper connected to the movable part with the set of offsets.