Optical switch, method of manufacturing same, and optical communication equipment using same

• US 6,487,330 B2
• Filed: 03/15/2001
• Issued: 11/26/2002
• Est. Priority Date: 02/17/1997
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd., Hitachi Cable Limited (Proterial Ltd.)
• Original Assignee: Hitachi, Ltd., Hitachi Cable Limited (Proterial Ltd.)
• Inventors: Akashi, Teruhisa, Kobayashi, Dai, Horino, Masaya, Komatsu, Norifumi, Muranishi, Masaru, Okano, Hiroaki, Sato, Kazutaka
• Primary Examiner(s): Kim, Ellen E.
• Application Number:
  US09/812,782
• Publication Number:
  US 20010017957A1
• Time in Patent Office: 621 Days
• Field of Search: 359/128, 385/16, 385/19.2, 370/85.7, 348/730, 348/373, 735/141--51
• US Class Current: 385/16
• CPC Class Codes: G02B 6/3502 involving direct waveguide displacement, e.g. cantilever type waveguide displacement involving waveguide bending, or displacing an interposed waveguide between stationary waveguides
• 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 6/3546 NxM switch, i.e. a regular array of switches elements of matrix type constellation
• CPC Class Codes: G02B 6/355 1x2 switch, i.e. one input and a selectable single output of two possible outputs
• CPC Class Codes: G02B 6/3566 involving bending a beam, e.g. with cantilever
• CPC Class Codes: G02B 6/3572 Magnetic force magnetic forces controlling reflecting elements in general G02B26/085; magneto-optic devices G02F1/09
• CPC Class Codes: G02B 6/3582 Housing means or package or arranging details of the switching elements, e.g. for thermal isolation
• 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

An optical switch for switching an optical path of an input optical signal comprises a substrate composed of a silica glass substrate, a separation layer formed on the silica glass substrate, a plurality of cantilever beams and formed in parallel to one another on the separation layer and connected at their tip ends to a connection member, at least one silica glass optical waveguide core formed on the cantilever beams, a plurality of optical waveguide fixed in opposition to the silica glass optical waveguide core, a cover for covering the cantilever beams, and a switch drive unit for bending the cantilever beams. The switch drive unit comprises electromagnetic actuators, which comprise soft magnetic bodies formed on the connection member for the cantilever beams and on the substrate, soft magnetic yokes formed of a soft magnetic body, permanent magnets, and wire coils.

Claims

1. An optical communication equipment comprising:

an optical signal input terminal, to which an optical video signal is input;

an electric signal input terminal, to which an electric audio signal is input;

an optical switch for switching an output of said optical video signal input from said optical signal input terminal;

an electro-optical signal converter for converting said electric signal from said electric signal input terminal to an optical signal and synthesizing the converted audio signal with an output optical signal from said optical switch; and

a controller having two output terminals from which the synthesized optical signal is output, for switching said optical switch upon judgment of an error in said synthesized signal from one of said two output terminals;

wherein said optical switch comprises;

a substrate made of a first material;

a separation layer formed on said substrate;

a plurality of cantilever beams formed in parallel to one another on said separation layer, and connected at tip ends thereof to a connection member;

at least one input optical waveguide core made of said first material and formed on said cantilever beams;

a plurality of output optical waveguide cores fixed in opposition to said at least one input optical waveguide core;

a press member fixed to said substrate to cross at least one of the tip ends of said cantilever beams;

a cover for covering the whole of said cantilever beams; and

switch drive means for shifting said cantilever beams.

2. The optical communication equipment as set forth in claim 1, wherein said first material is silica glass.

3. A method of fabricating an optical switch, comprising the steps of:

forming a separation layer on a silica glass substrate;

forming a silica glass buffer layer on said silica glass substrate so as to cover said separation layer;

forming a silica glass waveguide core on said silica glass buffer layer;

forming a silica glass clad layer on said silica glass buffer layer so as to cover said silica glass waveguide core;

forming external configurations of cantilever beams; and

removing said underlying separation layer of said cantilever beams so as to obtain a movable construction of said cantilever beams.

4. The method as set forth in claim 3, wherein the external configuration of said cantilever beams are formed by etching and the underlying separation layer of said cantilever beams is removed by etching.

5. An optical communication equipment comprising:

an optical signal input terminal, to which an optical video signal is input; and

an optical switch for switching an output of said optical video signal input from said optical signal input terminal, said optical switching including;

a silica glass substrate;

a seperation layer formed on said substrate;

a plurality of cantilever beams formed in parallel to one another on said seperation layer and floating above said silica glass substrate, and connected at their tip ends to a connection member, said cantilever beams being equally bendable in opposite directions;

a plurality of input silica glass optical waveguide cores, respective ones of said input silica glass optical waveguide cores being formed on respective ones of said cantilever beams so that each of said cantilever beams has a respective one of said input optical waveguide cores formed thereon;

a plurality of output optical waveguide cores fixed in opposition to said input silica glass optical waveguide cores; and

switch drive means for bending said cantilever beams from a position in one bent direction to a position in an opposite bent direction when an optical path switching operation is performed.

6. An optical communication equipment as set forth in claim 5, further comprising:

an electric signal input terminal to which an electrical audio signal is input;

an electro-optical signal converter for converting said electric signal from said electric signal input terminal to an optical signal and synthesizing the converted audio signal with an output optical signal from said optical switch; and

a controller having two output terminals from which the synthesized optical signal is output and for switching said optical switch upon judgement of an error in said synthesized signal from one of said two output terminals.

7. An optical communication equipment as set forth in claim 6, wherein said optical switch further comprises a separation layer formed on said silica glass substrate;

a press member fixed to said substrate to cross at least one of the tip ends of said cantilever beams; and

a cover for covering the entirety of said cantilever beams.

8. A method of manufacturing an optical path of an input optical signal, comprising the steps of:

forming a separation layer on a silica glass substrate;

forming on said separation layer a plurality of cantilever beams connected by a connection member, and disposing first optical waveguides on said cantilever beams;

forming a plurality of second optical waveguides disposed in opposition to said first optical waveguides; and

forming a switch drive for shifting optical paths of said first optical waveguides.

9. The method as set forth in claim 8, wherein said first optical waveguides comprise silica glass optical waveguides.

10. The method as set forth in claim 8, wherein said switch drive enables deforming of said cantilever beams so as to shift said optical paths.

11. The method as set forth in claim 8, wherein said separation layer is formed of at least one of silicone, titanium and platinum.

12. The method as set forth in claim 8, wherein said separation layer is formed to have a thickness smaller than a height of at least one of said first and second optical waveguides.

13. The method as set forth in claim 8, wherein said switch drive comprises a soft magnetic body provided on said connection member, a yoke being provided on said silica glass substrate and including a soft magnetic body, a permanent magnet, and a coil.