Environmentally rugged free-space fiber waveguide connector and method of manufacture thereof

Abstract

Various embodiments of free-space fiber waveguide connectors, feed-throughs and GRIN lens assemblies and methods of bonding GRIN lenses in, and aligning waveguide fibers to, such connectors, feed-throughs and assemblies. In one embodiment, a free-space fiber waveguide connector comprises a waveguide fiber mount including a fiber holder, a fiber waveguide, and a bonding agent bonding said fiber waveguide to said fiber holder, a coefficient of expansion of said fiber holder nominally matching a coefficient of expansion of said fiber waveguide and also nominally matching a coefficient of expansion of said bonding agent, said fiber waveguide having a surface oriented at a nonzero angle with respect to an axis of said fiber.

What is claimed is: 
     
         1 . A free-space fiber waveguide connector, comprising:
 a waveguide fiber mount including a fiber holder, a fiber waveguide, and a bonding agent bonding said fiber waveguide to said fiber holder, a coefficient of expansion of said fiber holder nominally matching a coefficient of expansion of said fiber waveguide and also nominally matching a coefficient of expansion of said bonding agent, said fiber waveguide having a surface oriented at a nonzero angle with respect to an axis of said fiber.   
     
     
         2 . The connector as recited in  claim 1  wherein said bonding agent is an epoxy. 
     
     
         3 . The connector as recited in  claim 1  wherein said bonding agent is a cement. 
     
     
         4 . The connector as recited in  claim 1  wherein said bonding agent is a glass frit. 
     
     
         5 . The connector as recited in  claim 1  wherein said nonzero angle is 90°. 
     
     
         6 . The connector as recited in  claim 1  wherein said planar surface angle is nominally 8° from said axis of said fiber waveguide. 
     
     
         7 . A free-space feed-through, comprising:
 a fiber holder;   a waveguide fiber; and   a glass frit hermetic seal securing said waveguide fiber within said fiber holder, a coefficient of expansion of said fiber holder nominally matching a coefficient of expansion of said fiber waveguide and also nominally matching a coefficient of expansion of said glass frit.   
     
     
         8 . A method of bonding a GRIN lens, comprising:
 polishing a surface of said GRIN lens and a surface of another material;   placing said surfaces adjacent one another; and   applying a substantial electric field across said surfaces to place said surfaces into opposite ionic states.   
     
     
         9 . The method as recited in  claim 8  wherein said other material is a glass. 
     
     
         10 . The method as recited in  claim 8  wherein said other material is a ceramic. 
     
     
         11 . The method as recited in  claim 8  wherein said other material is a transparent media. 
     
     
         12 . A method of aligning a fiber to a virtual axis of a GRIN lens, comprising:
 bonding said GRIN lens to a beveled, transparent plate, said plate defining a reference plane perpendicular to said virtual axis;   placing a reference reflector parallel to said reference plane;   injecting a signal into said fiber;   adjusting a position of said fiber until at least a near-maximum reflected signal is achieved; and   bonding said fiber at said position.   
     
     
         13 . The method as recited in  claim 12  further comprising repeating said bonding for a plurality of GRIN lenses.