Shaping mold, optical fiber guide block, processes for the production thereof, and optical fiber array

Abstract

Disclosed are a shaping mold for producing an optical fiber guide block which permits highly accurate positioning and fixing of optical fibers, an optical fiber guide block having such excellent properties, processes for the production of these, and an optical fiber array. The shaping mold comprises an elevated region and a circumferential region adjacent to the elevated region, the elevated region having a plurality of convex portions designed for shaping the optical fiber fitting portions and having a side surface forming a boundary with the circumferential region, the boundary being positioned at a level lower than the level of bottoms of grooves formed between one convex portion and another convex portion, said side surface being an additional side surface different from side surfaces of any convex portions designed for shaping optical fiber fitting portions, the optical fiber guide block has a specific form produced by a mold shaping method using the above shaping mold, and the optical fiber array comprises the above optical fiber guide block.

What is claimed is:  
     
         1 . A shaping mold having transfer shaping surfaces for producing an optical fiber guide block having a plurality of optical fiber fitting portions in the form of grooves and a side region in the vicinity of a region where the optical fiber fitting portions are formed, the shaping mold comprising an elevated region and a circumferential region adjacent to the elevated region, the elevated region having a plurality of convex portions designed for shaping the optical fiber fitting portions and having a side surface forming a boundary with the circumferential region, the boundary being positioned at a level lower than the level of bottoms of grooves formed between one convex portion and another convex portion, said side surface being an additional side surface different from side surfaces of any convex portions designed for shaping optical fiber fitting portions.  
     
     
         2 . The shaping mold of  claim 1 , which has two circumferential regions formed on both sides of the elevated region and positioned substantially at one level.  
     
     
         3 . The shaping mold of  claim 1 , wherein the elevated region has a secondary convex portion which continues to the additional side surface and is positioned along the side surface of the convex portion designed for an optical fiber fitting portion which convex portion is closest to the additional side surface.  
     
     
         4 . A process for the production of a shaping mold having transfer shaping surfaces for producing an optical fiber guide block having a plurality of optical fiber fitting portions in the form of grooves and side portions in the vicinities of a region where the optical fiber fitting portions are formed, the process comprising the steps of 
 forming a plurality of convex portions in a mold material, the convex portions being designed for transfer-shaping the optical fiber fitting portions, and    forming a circumferential region in the mold material,    the step of forming the circumferential region including the formation of a side surface of an elevated region, which side surface is an additional side surface different from side surfaces of any convex portions,    the step of forming the circumferential region further including the formation of a boundary with the circumferential region at a level lower than the level of bottoms of grooves formed between one convex portion and another convex portion.    
     
     
         5 . The process of  claim 4 , wherein the step of forming the circumferential region is carried out to form two circumferential regions which are on both sides of the elevated region and positioned substantially at one level.  
     
     
         6 . The process of  claim 4 , wherein the step of forming the convex portion designed for shaping optical fiber fitting portions and the step of forming the circumferential region are carried out to form a secondary convex portion which continues to the additional side surface and is positioned along the side surface of the convex portion designed for an optical fiber fitting portion which convex portion is closest to the additional side surface.  
     
     
         7 . An optical fiber guide block comprising a region of a plurality of optical fiber fitting portions formed in one surface in the form of grooves and a side region adjacent to the region of the optical fiber fitting portions, the optical fiber guide block being formed by a mold-shaping method, the optical fiber fitting portions having boundaries between one optical fiber fitting portion and another optical fiber fitting portion, the boundaries having peaks or peak surfaces at a level lower than the level of the side region edge on the side of the region of the optical fiber fitting portions, the side region having an additional side surface which is different from any optical-fiber-supporting side surfaces of the optical fiber fitting portions and which is on the side of the region of the optical fiber fitting portions.  
     
     
         8 . The optical fiber guide block of  claim 7 , wherein the optical fiber guide block has two side regions adjacent to the region of the optical fiber fitting portions and the two side regions have upper surfaces positioned at one level.  
     
     
         9 . The optical fiber guide block of  claim 7 , wherein the region of the optical fiber fitting portions has a secondary concave portion which continues to the additional side surface and is positioned along the optical fiber fitting portion closest to the additional side surface.  
     
     
         10 . The optical fiber guide block of  claim 7 , wherein the optical fiber guide block has an accumulated pitch accuracy between one of the optical fiber fitting portions formed in outermost positions and any other optical fiber fitting portion, which accumulated pitch accuracy is equivalent to an accumulated pitch accuracy between any two optical fiber guide blocks other than the optical fiber fitting portions formed in the outermost positions.  
     
     
         11 . The optical fiber guide block of  claim 7 , wherein the optical fiber guide block has an accumulated pitch accuracy of within ±0.5 μm between one of the optical fiber fitting portions formed in outermost positions and any other optical fiber fitting portion.  
     
     
         12 . The optical fiber guide block of  claim 7 , wherein one of the optical fiber fitting portions formed in outermost positions when an optical fiber is positioned and fixed in said optical fiber fitting portion has a height accuracy equivalent to a height accuracy in the optical fiber fitting portion other than the optical fiber fitting portions formed in the outermost positions when the same optical fiber is positioned and fixed in said optical fiber fitting portion.  
     
     
         13 . The optical fiber guide block of  claim 7 , wherein any optical fiber fitting portion when an optical fiber is positioned and fixed therein has a height accuracy of within ±5 μm.  
     
     
         14 . A process for the production of an optical fiber guide block comprising a region of a plurality of optical fiber fitting portions in the form of grooves and a side region adjacent to the region of the optical fiber fitting portions by a mold shaping method, 
 the process comprising providing the shaping mold recited in  claim 1  and mold-shaping a shapeable material into the optical fiber guide block with the shaping mold,    the optical fiber fitting portions having boundaries between one optical fiber fitting portion and another optical fiber fitting portion, the boundaries having peaks or peak surfaces at a level lower than the level of the side region edge on the side of the region of the optical fiber fitting portions, the side region having an additional side surface which is different from any optical-fiber-supporting side surfaces of the optical fiber fitting portions and which is on the side of the region of the optical fiber fitting portions.    
     
     
         15 . The process of  claim 14 , wherein the mold shaping is carried out to form two side regions which are adjacent to the region of the optical fiber fitting portions and have upper surfaces positioned at one level.  
     
     
         16 . The process of  claim 14 , wherein the mold shaping is carried out to form a secondary concave portion which continues to the additional side surface and is positioned along the optical fiber fitting portion closest to the additional side surface.  
     
     
         17 . The process of  claim 14 , wherein the shapeable material is a preform formed of glass.  
     
     
         18 . An optical fiber array comprising the above optical fiber guide block, a predetermined number of optical fibers fitted in optical fiber fitting portions of the optical fiber guide block and a pressing member used for pressing and fixing the optical fibers to the optical fiber fitting portions, at least the optical fiber guide block and the pressing member being bonded and fixed to each other.