Modular laser connector packaging system and method
A module for optically and structurally coupling a light diffusion optical fiber to a laser diode on a substrate in a compact module includes a fiber holder into which an exposed core of the laser extends and which is placed about the laser 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, wherein the optical fiber comprises a core tip exposed and extending from the fiber cladding at a light receiving end of the fiber and wherein the substrate is a printed circuit board comprising a top surface on which the laser or LED light source is disposed, a bottom surface, and a periphery, the method comprising:
extending the exposed core tip into a fiber holder through an aperture in a closed end of the fiber holder;
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, wherein the strain relief housing is made of rubber; and
inserting said fiber holder and the top surface and periphery of said printed circuit board into said strain relief housing in water resistant sealing relation such that the periphery of said printed circuit board abuts an interior surface of said strain relief housing proximate an open end of said strain relief housing.
2. The method of claim 1 wherein the light source comprises 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 the printed circuit board has 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 the 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. A module assembly for optically and structurally coupling an optical fiber to a light source, the module assembly 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 a top surface, a bottom surface, and a periphery, wherein the substrate is a printed circuit board and wherein the light source is 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 the top surface and periphery of said substrate, wherein said resilient strain relief housing is made of rubber and wherein said housing has an open end with an interior surface, said interior surface abutting the periphery in sealing engagement.
11. The module assembly of claim 10 further comprising a plurality of electrical leads extending from said module at the bottom surface of said substrate.
12. The module of claim 10 wherein said light source is selected from the group consisting of a VCSEL and a LED.
13. The module of claim 10 wherein said fiber core tip is spaced from said light source by a gap no greater than a few hundred microns.
14. The module of claim 13 wherein said gap is filled with epoxy having a refractive index matching the refractive index of the optical fiber.
15. The module of claim 10 further comprising electronic components disposed on said top surface of said substrate and within said housing.
16. The module of claim 10 wherein said fiber holder has a generally cylindrical cup-like configuration.