Optical fiber array and method of fabrication thereof

An optical fiber array is presented, in which the adherence of a lower substrate to an upper substrate is good, and no stress concentrations occur in the optical fibers. In a lower substrate 2 , V-grooves 3 are formed that have an inscribed circle A that is formed between the V-grooves and the virtual plane of the upper surface of the lower substrate, and which is larger than the optical fibers 1 that are accommodated in the V-grooves 3 . A UV curing adhesive 5 of a 2000 cp viscosity is filled into the V-grooves 3 , and the optical fibers 1 are arranged within the V-grooves 3 . Next, a predetermined amount of UV rays are irradiated on the adhesive 5 to raise its viscosity to at least 3000 cp, after which an upper substrate 4 is arranged on the optical fibers 1 and pressure adhered, and UV rays are irradiated a again to completely cure the adhesive 5.