Modular Laser Connector Packaging System and Method

Abstract

A module for optically and structurally coupling a light diffusion optical fiber to a laser or LED diode on a substrate in a compact module includes a fiber holder into which an exposed core of the laser or LED extends and which is placed about the laser or LED on a substrate such that the laser and fiber are axially aligned in butt coupled relation. A resilient strain relief housing is secured about the light receiving end of the fiber, and the fiber holder and substrate are inserted into the housing in a secured in a water sealing engagement.

1 . A method for optically and structurally coupling an optical fiber to a laser or LED light source on a substrate in a compact module comprising:
 providing an optical fiber with a core tip exposed and extending from the fiber cladding at a light receiving end of the fiber;   extending the exposed core tip into a fiber holder through an aperture in a closed end of the fiber holder;   disposing a laser or LED light source on a top surface of a substrate;   positioning an open end of the fiber holder on the top surface of the substrate surrounding said light source with the exposed fiber core tip in light-receiving butt-coupled relation to said light source;   securing a resilient strain relief housing about the light receiving end of said fiber; and   inserting said fiber holder and at least the top surface of said substrate into said strain relief housing in water resistant sealing relation.   
     
     
         2 . The method of  claim 1  wherein disposing a light source comprises providing a VCSEL on the top surface of the substrate. 
     
     
         3 . The method of  claim 1  wherein positioning an open end of the fiber holder includes leaving a gap in the range of a few microns to a couple of hundred microns between the butt-coupled light source and the exposed core tip of the optical fiber. 
     
     
         4 . The method of  claim 3  further comprising filling said gap with epoxy having a refractive index matching the refractive index of the optical fiber. 
     
     
         5 . The method of  claim 1  wherein said substrate is a printed circuit board having electronic components on said top surface, and wherein inserting the top surface of the substrate includes securing the housing about the substrate and the electronic components. 
     
     
         6 . The method of  claim 5  further comprising extending electrical leads from a bottom surface of said substrate outside said housing. 
     
     
         7 . The method of  claim 1  wherein the fiber holder is provided in a generally cylindrical cup-like configuration. 
     
     
         8 . The method of  claim 1  wherein said fiber holder is provided as a transparent encapsulation epoxy having a refractive index matching the refractive index of the optical fiber. 
     
     
         9 . The method of  claim 1  wherein said positioning an open end of the fiber holder on the top surface of the substrate comprises employing a pick and place robotic system to so position the fiber holder. 
     
     
         10 . The method of  claim 1  wherein the step of inserting includes abutting the periphery of said substrate is sealing relation to an interior surface of said strain relief housing proximate an open end of said strain relief housing. 
     
     
         11 . A module assembly for optically and structurally coupling an optical fiber to a light source such as a laser or LED comprising:
 an optical fiber having a light-receiving end, an optically transmissive core and a cladding surrounding said core, wherein a portion of said core extends axially from said cladding at said light-receiving end;   a fiber holder having an open end and a closed end with an aperture defined through said closed end;   wherein the light-receiving end of said optical fiber is secured to said fiber holder with said core tip extending though said aperture into said holder;   a substrate having top and bottom surfaces;   a light source such as a laser or LED disposed on said top surface of said substrate;   wherein the open end of said of said fiber holder is secured to the top surface of said substrate surrounding said light source with said fiber core tip butt-coupled to the light in light-receiving relation; and   a resilient strain relief housing enclosing and providing water resistant sealing for the light receiving end of said fiber, said fiber holder and at least the top surface of said substrate.   
     
     
         12 . The module assembly of  claim 11  wherein said substrate has a defined periphery, wherein said housing has an open end with an interior surface, and wherein said interior surface abuts said defined periphery in sealing engagement. 
     
     
         13 . The module assembly of  claim 12  further comprising a plurality of electrical leads extending from said module at the bottom surface of said substrate. 
     
     
         14 . The module of  claim 11  wherein said light source is selected from the group consisting of a VCSEL and a LED. 
     
     
         15 . The module of  claim 11  wherein said fiber core tip is spaced from said light source by a gap no greater than a few hundred microns. 
     
     
         16 . The module of  claim 15  wherein said gap is filled with epoxy having a refractive index matching the refractive index of the optical fiber. 
     
     
         17 . The module of  claim 11  further comprising electronic components disposed on said top surface of said substrate and within said housing. 
     
     
         18 . The module of  claim 11  wherein said fiber holder has a generally cylindrical cup-like configuration. 
     
     
         19 . The module of  claim 11  wherein said resilient strain relief housing is made of rubber. 
     
     
         20 . The module of  claim 11  wherein said substrate is a printed circuit board.