Multi-piece fiber optic component and manufacturing technique

Abstract

An apparatus to accurately hold an optical fiber within a commercial fiber optic connector. The connector has a first high precision slice having multiple holes of a first area and a first alignment opening and a second high precision slice having multiple holes of a second area and a second alignment opening. The holes of the first high precision slice are arranged relative to the first alignment opening so that, when the second high precision slice and the first high precision slice are juxtaposed with one another and the first alignment opening and the second alignment opening are aligned, the holes of the first high precision slice and the holes of the second high precision slice will be offset relative to each other and will define an opening having an area less than a smaller of the first area and second area. The opening is capable of closely constraining an optical fiber inserted therethrough. A method of making a fiber optic connector adapted to receive a fiber bearing unit involves coupling at least two high precision pieces, having misaligned holes relative to each other, together coupling the at least two high precision pieces to a low precision piece to form a unit, inserting optical fibers into the unit, terminating the fibers in the holes, and housing the unit within a fiber optic connector housing.

What is claimed is:  
     
         1 . An apparatus to accurately hold an optical fiber within a commercial fiber optic connector comprising: 
 a first high precision slice having multiple holes of a first area and a first alignment opening;    a second high precision slice having multiple holes of a second area and a second alignment opening;    the holes of the first high precision slice being arranged relative to the first alignment opening so that, when the second high precision slice and the first high precision slice are juxtaposed with one another and the first alignment opening and the second alignment opening are aligned, the holes of the first high precision slice and the holes of the second high precision slice will be offset relative to each other and define an opening having an area less than a smaller of the first area and second area and capable of closely constraining an optical fiber inserted therethrough.    
     
     
         2 . The apparatus of  claim 1  wherein the first area and the second area are equal.  
     
     
         3 . The apparatus of  claim 2  wherein the first hole has a substantially circular cross section.  
     
     
         4 . The apparatus of  claim 2  wherein the first hole has a substantially oval cross section.  
     
     
         5 . The apparatus of  claim 1  wherein the first slice comprises silicon wafer and the holes are created using an isotropic wet etch process.  
     
     
         6 . The apparatus of  claim 5  wherein the isotropic wet etch process is a KOH etch.  
     
     
         7 . The apparatus of  claim 2  wherein the second piece comprises silicon wafer and the holes are created using an anisotropic etch process.  
     
     
         8 . The apparatus of  claim 7  wherein the anisotropic etch process is a Bosch process.  
     
     
         9 . The apparatus of  claim 1  wherein the second piece holes are created using a drilling process.  
     
     
         10 . An apparatus to constrain an optical fiber having a cross sectional diameter, the apparatus comprising: 
 two pieces each cleaved from a silicon wafer, each of the pieces having a first side and a second side, alignment holes, and an array of fiber holes of substantially circular cross section, the fiber holes having been formed by 
 i) photoresist patterning fiber hole locations on a surface of the silicon wafer,  
 ii) performing a Bosch etch on the surface of the silicon wafer to create the fiber holes, and  
 iii) performing a clean up etching of the holes,  
 each of the fiber holes on the two pieces having a diameter larger than the cross sectional diameter and being located such that, when the first side of one piece is placed against the first side of the other piece and the alignment holes are aligned, the fiber holes of the two pieces will define a biconvex opening having a width of approximately equal to the cross sectional diameter.  
   
     
     
         11 . The apparatus of  claim 10  wherein the optical fiber is a single mode optical fiber.  
     
     
         12 . The apparatus of  claim 11  wherein the fiber holes were further created by orienting the silicon wafer to a particular angular orientation after i) but before ii) and performing ii) with the silicon wafer at the particular orientation so that when the alignment holes on the two pieces are aligned the fiber holes on the two pieces will be in axial alignment and the axes will be offset from a perpendicular to the first side.  
     
     
         13 . The apparatus of  claim 10  wherein the optical fiber is a multimode optical fiber.  
     
     
         14 . A fiber holder of a size suitable for use in a commercial fiber optic connector comprising: 
 a first piece having a thickness, a periphery defining a first surface and a second surface opposite the first surface,    the first piece further having an array of fiber receiving holes of a first substantially circular cross sectional area and extending through the thickness;    a second piece having a thickness and a periphery defining a first surface and a second surface opposite the first surface,    the second piece further having an array of fiber receiving holes of a second substantially circular cross sectional area and extending through the thickness;    The first piece and the second piece being coupled together such that, when the first piece and the second piece are coupled to a low precision piece having a ferrule shaped peripheral surface, centers of the fiber receiving holes in the first piece are offset from centers of the fiber receiving holes in the second piece by an amount sufficient to closely constrain optical fibers inserted therethrough.    
     
     
         15 . The fiber holder of  claim 14  wherein the first substantially circular cross sectional area is the same as the second substantially circular cross sectional area.  
     
     
         16 . The fiber holder of  claim 14  wherein the first substantially circular cross sectional area is larger than the second substantially circular cross sectional area.  
     
     
         17 . The fiber holder of  claim 14  wherein the first piece and the second piece were formed on a common wafer.  
     
     
         18 . The fiber holder of  claim 14  wherein the first piece and the second piece are substantially identical.  
     
     
         19 . The fiber holder of  claim 14  wherein the commercial fiber optic connector is one of an MTP, MPO or MPX connector.  
     
     
         20 . A commercial fiber optic connector of a style constructed to accept a ferrule-like unit therein, the commercial fiber optic connector comprising: 
 a connector housing,    single mode optical fibers having first ends, second ends and a fiber cross sectional area,    a low precision piece, and    two abutting high precision slices each having a surface and fiber holes therein, each of the fiber holes being of a cross sectional area larger than the fiber cross sectional area and being offset from a perpendicular to the surface at an angle of up to about 8 degrees, and offset with respect to each other so as to define an opening smaller than the cross sectional areas of a sufficient size relative to the fiber cross sectional area to closely constrain the single mode fibers therebetween,    the low precision piece being coupled to the two high precision slices,    the low precision piece and the two high precision slices collectively forming the ferrule like unit, and    the ferrule like unit being contained substantially within the connector housing.    
     
     
         21 . The commercial fiber optic connector of  claim 20  wherein the style is one of an MTP style, MPO style or MPX style.  
     
     
         22 . The commercial fiber optic connector of  claim 20 , further comprising: 
 an alignment piece, contained within the connector housing, and having posts extending through at least one of the low precision piece or a high precision slice.    
     
     
         23 . A method of making an optical fiber holder usable in a commercial connector, the method comprising: 
 making holes of a first size in a first plate, the first size being larger than a cross sectional area of an optical fiber;    making holes of a second size in a second plate, the second size being larger than the cross sectional area of the optical fiber;    misaligning the holes in the first plate relative to the holes in the second plate such that the holes in the first plate partially overlap the holes in the second plate by an amount that will create openings of at least the cross sectional area and having a sufficient shape to accept optical fibers inserted through the holes and also closely constrain the optical fibers inserted therein.    
     
     
         24 . The method of  claim 23  wherein the misaligning comprises: 
 inserting the first plate and the second plate onto alignment pins.  
 
     
     
         25 . The method of  claim 23  wherein the making the holes in the first plate comprises making holes of a substantially circular cross section.  
     
     
         26 . The method of  claim 23  wherein the making the holes in the first plate comprises making holes of a substantially oval cross section.  
     
     
         27 . A method of making a fiber optic connector adapted to receive a fiber bearing unit, comprising: 
 coupling at least two high precision pieces, having misaligned holes relative to each other, together and configured to, when misaligned, accept an array of optical fibers inserted therein,    coupling the at least two high precision pieces to a low precision piece to form a unit,    inserting optical fibers into the unit,    terminating the fibers in the holes, and    housing the unit within a fiber optic connector housing.