Optical switch with mobile components and method for making same

• US 6,833,080 B2
• Filed: 10/01/2002
• Issued: 12/21/2004
• Est. Priority Date: 04/17/2000
• Status: Expired due to Fees

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Inventors: Pouteau, Patrick, Margail, Jacques
• Primary Examiner(s): Mills, Gregory
• Assistant Examiner(s): CULBERT, ROBERTS P
• Application Number:
  US10/239,845
• Publication Number:
  US 20030138191A1
• Time in Patent Office: 812 Days
• Field of Search: 216/2, 216/24, 385/16, 385/18, 359/197, 359/212, 359/214, 359/223, 359/224, 359/225, 359/226, 359/291, 359/872
• US Class Current: 216/24
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 6/3514 the reflective optical element moving along a line so as to translate into and out of the beam path, i.e. across the beam path
• CPC Class Codes: G02B 6/3518 the reflective optical element being an intrinsic part of a MEMS device, i.e. fabricated together with the MEMS device MEMS devices in general B81B; manufacture of MEM devices in general B81C; micromechanical devices controlling the direction of light G02B26/0833
• CPC Class Codes: G02B 6/3546 NxM switch, i.e. a regular array of switches elements of matrix type constellation
• CPC Class Codes: G02B 6/357 Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841
• CPC Class Codes: G02B 6/358 Latching of the moving element, i.e. maintaining or holding the moving element in place once operation has been performed; includes a mechanically bistable system
• 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

Abstract

Optical switch comprising optical means (120) and driving means (114, 115, 124) on a substrate (100), cooperating with optical means to make them pivot between a rest position and at least one active position. According to the invention, the switch comprises first mobile stop means (122), rigidly fixed to the optical means (120, 130) so that they can pivot with the optical means, and second fixed stop means (128) arranged in a plane approximately parallel to the main face (110) of the substrate and cooperating with the first stop means, to fix the said active position of the optical means.

Application to make an optical cross connect.

Claims

1. An integrated optical switch comprising an optical means on a substrate capable of interacting with a switching light, and a driving means cooperating with the optical means to make them pivot between a first rest position and at least one second active position, the first optical means rigidly fixed to the optical means so that they can be pivoted with the optical means, and the second fixed stop means formed in a plane approximately parallel to a main face of the substrate and cooperating with the first stop means to fix the said active position of the optical means, the first stop means and the optical means are connected to the substrate by a torsion beam extending along a pivot axis forming a single assembly with the torsion beam, and in the rest position the optical means extends approximately parallel to the main face of the substrate, the switch being characterized in that the angular spacing between the first stop means and the optical means is approximately a right angle.

2. A switch according to claim 1, in which the driving means comprise at least one mobile electrode fixed to the optical means so that it can pivot with the optical means, and at least one fixed electrode that is rigidly attached to the substrate, associated with a corresponding mobile electrode to exert electrostatic pivoting forces between each mobile electrode and the corresponding fixed electrode.

3. A switch according to claim 2, in which the first stop means forms at least one mobile electrode.

4. A switch according to claim 2, in which the first stop means carries at least one mobile electrode.

5. A switch according to claim 1, in which the optical means comprises at least one of a mirror, a separating strip, a lens, a plate of an absorbent material, and a plate of a reflecting material.

6. A switch according to claim 1 in which the optical means has a first part with a first optical property, upright on the substrate in a first active position, and a second part with a second optical property, different from or the same as the first optical property, upright on the substrate in a second active position.

7. An optical cross connecting device comprising several optical switches according to claim 1, arranged in lines and rows of optical switches, an optical input channel being associated with each line or each row of switches and an optical output channel being associated with each row or line of the switch.

8. A cross connecting device according to claim 7, comprising several optical fibers coupled to the lines and rows of optical switches, respectively.

9. A switch according to claim 1, characterized in that the substrate is divided into two parts attached by plane contact faces, one of the parts carrying the second stop means and the other carrying parts supporting the assembly consisting of the torsion beam the first stop means and the second stop means.

10. A process for manufacturing an integrated optical switch comprising an optical means on a substrate capable of interacting with a switching light, and a driving means cooperating with the optical means to make them pivot between a first rest position and at least one second active position, the first optical means rigidly fixed to the optical means so that they can be pivoted with the optical means, and the second fixed stop means formed in a plane approximately parallel to a main face of the substrate and cooperating with the first stop means to fix the said active position of the optical means, the first stop means and the optical means are connected to the substrate by a torsion beam extending along a pivot axis forming a single assembly with the torsion beam, and in the rest position the optical means extends approximately parallel to the main face of the substrate, the switch being characterized in that the angular spacing between the first stop means and the optical means is approximately a right angle, comprising the following steps in sequence:

forming at least one fixed electrode on a main face of a first substrate and defining an optical means on a second substrate parallel to the main face of the second substrate;

assembling the first and second substrates by putting the main faces facing each other; and

after said assembling, etching the second substrate by a free rear face opposite the main face, to form at least one mobile stop in the substrate, rigidly fixed to the optical means, and to release the optical means.

11. A process according to claim 10, in which a second substrate made from a non-insulating material is used such that the mobile stop forms an electrode.

12. A process according to claim 10, further comprising forming an electrode on the mobile stop.

13. A process according to claim 10, in which the step of forming further comprises etching at least one cavity in the first substrate to contain the optical means.

14. A process according to claim 10, in which the step of forming further comprises defining at least one fixed stop in the first substrate cooperating with the mobile stop formed in the second substrate to fix a position of the optical means in the active position and/or the rest position.

15. A process according to claim 10, in which the second substrate comprises a surface layer separated from a solid part by a buried layer in which a plate forming the optical means and torsion bars connecting the plate to a fixed part of the surface layer are defined by etching the surface layer.

16. A process according to claim 15, in which a layer of an optical material is deposited on said surface layer in a region in which said plate is defined.

17. A process according to claim 15, in which the step of etching further comprises etching the second substrate with a stop on the buried layer.

18. A process according to claim 15, in which the second substrate is of the SOI (Silicon On Insulator) type.

19. A process according to claim 10, in which at least one groove is etched to enable movement of the optical means in the first substrate.