Optical switch

• US 7,379,636 B2
• Filed: 12/18/2006
• Issued: 05/27/2008
• Est. Priority Date: 03/02/2001
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Oikawa, Yoichi, Kuroyanagi, Satoshi
• Primary Examiner(s): Wood; Kevin S
• Application Number:
  US11/640,221
• Publication Number:
  US 20070098321A1
• Time in Patent Office: 526 Days
• Field of Search: 385 18- 24
• US Class Current: 385/18
• CPC Class Codes: G02B 2006/12145 Switch
• CPC Class Codes: G02B 6/122 Basic optical elements, e.g. light-guiding paths
• CPC Class Codes: G02B 6/3512 the optical element being reflective, e.g. mirror
• 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 6/3538 based on displacement or deformation of a liquid controlling the intensity of light by displacement or deformation of a fluid in general G02B26/004; fluid-filled lens of variable focal length G02B3/14
• CPC Class Codes: G02B 6/3546 NxM switch, i.e. a regular array of switches elements of matrix type constellation
• CPC Class Codes: G02B 6/356 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 6/3582 Housing means or package or arranging details of the switching elements, e.g. for thermal isolation
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/0024 using space switching
• CPC Class Codes: H04Q 2011/003 using switches based on microelectro-mechanical systems [MEMS]

Abstract

An optical switch having a plurality of switch cells. The optical switch has n inputs (n is a natural number) and m outputs (m is a natural number). The optical switch has a unit size defined as the distance between any two adjacent ones of the switch cells. The optical switch comprises a substrate having a switch size of K×L (K is an integer satisfying n≦K, and L is an integer satisfying m≦L), first and second mirrors parallel to each other and perpendicular to a principal surface of the substrate, and an optical unit providing a plurality of input optical paths for the n inputs and a plurality of output optical paths for the m outputs. The plurality of input optical paths are inclined relative to the first and second mirrors, and the plurality of output optical paths are inclined relative to the first and second mirrors. Each switch cell comprises a switch mirror provided movably relative to the substrate. With this configuration, the path dependence of loss is substantially eliminated.

Claims

1. An optical switch comprising:

a plurality of optical input ports;

a plurality of optical output ports; and

a plurality of optical path switching means provided between said plurality of optical input ports and said plurality of optical output ports, each of said plurality of optical path switching means having a movable optical reflecting member; and

reflecting means provided between said plurality of optical input ports and said plurality of optical output ports so as to interpose said plurality of optical path switching means for reflecting light from said optical input ports or light from said optical path switching means;

wherein;

each movable optical reflection member of the plurality of optical path switching means has one of first, second and third reflection types, the first reflection type reflecting light to an only first direction, the second reflection type reflecting light to an only second direction which is reverse to the first direction, the third reflection type reflecting light to both the first and second directions, all of the first, second and third reflection types being used in the movable optical reflection members of the plurality of optical path switching means;

said plurality of reflecting means and reflecting means are arranged so that path lengths from said optical input ports to said optical output ports are equal; and

each of said plurality of optical path switching means is located at a lattice of a matrix which is n rows (n is a natural number and greater than

     2)×

m columns (m is a natural number and greater than

     2), and lights from an adjacent optical path switching means located at (j−

1)th column (1≦

(j−

1)≦

(m−

1) cross each other and are inputted to adjacent optical path switching means located at j-th column.

2. An optical switch comprising:

a plurality of optical input ports;

a plurality of optical output ports; and

a plurality of optical path switching means provided between said plurality of optical input ports and said plurality of optical output ports, each of said plurality of optical path switching means having a movable optical reflecting member; and

reflecting means provided between said plurality of optical input ports and said plurality of optical output ports so as to interpose said plurality of optical path switching means for reflecting light from said optical input ports or light from said optical path switching means;

wherein;

each movable optical reflection member of the plurality of optical path switching means has one of first, second and third reflection types, the first reflection type reflecting light to an only first direction, the second reflection type reflecting light to an only second direction which is reverse to the first direction, the third reflection type reflecting light to both the first and second directions, all of the first, second and third reflection types being used in the movable optical reflection members of the plurality of optical path switching means;

said plurality of reflecting means and reflecting means are arranged so that path lengths from said optical input ports to said optical output ports are equal; and

each of said plurality of optical path switching means is located at a lattice of a matrix which is n rows (n is a natural number and greater than

     2)×

m columns (m is a natural number and greater than

     2), and a light from a first optical path switching means located at i-th row (1≦

i≦

n−

1) and j−

1)-th column (1≦

(j−

1)≦

(m−

1)) is inputted to a second optical path switching means located at (i+1)-th row and j-th column and a light from a third optical path switching means located at (i+1)-th row and (j−

1)-th column is inputted to a fourth optical path switching means located at i-th row and j-th column.