Planar array optical switch and method

• US 7,483,602 B2
• Filed: 05/26/2006
• Issued: 01/27/2009
• Est. Priority Date: 06/05/1998
• Status: Expired due to Fees

• Current Assignee: Lumentum Operations, LLC (Lumentum Holdings Inc.)
• Original Assignee: AFN, LLC (GlobalTranz Enterprises LLC)
• Inventors: Krozier, David A., Plouffe, Leo A., Laor, Herzel
• Primary Examiner(s): Font; Frank G
• Assistant Examiner(s): LEPISTO, RYAN A
• Application Number:
  US11/420,698
• Publication Number:
  US 20070053630A1
• Time in Patent Office: 977 Days
• Field of Search: 385/18
• US Class Current: 385/18
• CPC Class Codes: G02B 6/32 having lens focusing means positioned between opposed fibre ends with lens being an integral part of the single fibre end G02B6/262
• CPC Class Codes: G02B 6/3512 the optical element being reflective, e.g. mirror
• 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 6/3542 Non-blocking switch, e.g. with multiple potential paths between multiple inputs and outputs, the establishment of one switching path not preventing the establishment of further switching paths
• CPC Class Codes: G02B 6/3556 NxM switch, i.e. regular arrays 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 6/3584 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: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/0024 using space switching
• CPC Class Codes: H04Q 2011/0026 using free space propagation (e.g. lenses, mirrors)
• CPC Class Codes: H04Q 2011/003 using switches based on microelectro-mechanical systems [MEMS]

Abstract

An optical switch device includes a first array (20) of reflectors (22), each associated with a separate optical fiber input (12), and a second array (30) of reflectors (32), each associated with a separate fiber output (14). The reflectors (22 and 32) are positionable to direct an optical signal from any one of the fiber inputs (12) to any one of the fiber outputs (14). The optical signal is directed along an optical pathway between the desired fiber output (14) and its associated reflector that is substantially aligned with an axis extending centrally from the fiber output. Preferably, symmetrical fiber beam forming units for forming the optical signal into a focused beam are included between the fiber inputs (12) and the first array as well as between the second array (20) and the fiber outputs (14). A method for switching optical signals between an input and an output optical fiber end involves forming the optical signal emitted from the input fiber end into a focused beam wherein rays from a point on the input fiber end are convergent. The focused beam is directed towards the output fiber end using at least two positionable reflectors oriented to direct the signal so that, prior to reaching the fiber output, it propagates along an optical pathway that is substantially aligned with an axis extending centrally from the output fiber end.

Claims

1. An optical switch for directing an optical signal between a first fiber end and a selected second fiber end of a plurality of output fibers, said optical switch comprising:

first focusing optics, disposed in known spatial relation to the first fiber end, for receiving said optical signal from said input fiber end and forming a focused beam, wherein said focused beam includes rays that converge to create an image of the first fiber on second focusing optics;

said second focusing optics being operative for imaging the second fiber end onto the first focusing optics, wherein said second focusing optics is disposed in known spatial relation to the selected second fiber end, and is operative for receiving said focused beam from said beam directing unit and focusing said focused beam onto the selected second fiber end;

wherein said first focusing optics includes a first lens having a first surface facing the input fiber end and a second surface facing opposite said first surface of said first lens, and said second focusing lens is a second lens having a first surface facing the output fiber end and a second surface facing opposite said first surface of said second lens; and

a beam directing unit, optically disposed relative to said first focusing optics for receiving said focused beam, for selectivity directing said focused beam relative to said selected second fiber end so as to optically connect said first fiber end and said selected second fiber end for transmission of said optical signal therebetween;

wherein with D representing the effective aperture of said first and second lenses, u representing the distance between said first lens and the input fiber end and the distance between said second lens and the output fiber end, v representing the distance between said first and second lenses, NA representing the numerical aperture of the input and output fiber ends, and f representing the focal length of said first and second lenses, the following equations are satisfied;

D=2 u tan(sin<sup>−

1</sup>(N.A.))+d

l/f=l/v+l/u

d/u =D/v

when a thin lens approximation is assumed.

2. The optical switch device of claim 1 wherein said beam directing unit comprises a first reflector and a second reflector.

3. The optical switch device of claim 2 wherein said reflectors are micro electro mechanical mirrors.

4. The optical switch device of claim 3 wherein each of said mirrors is rotatable about at least one axis.