OPTICAL FILTERING DEVICE AND METHOD OF MAKING THE SAME

摘要

A method for making an optical filtering device having any desired number N of optical ports, where Nm(G)2. The apparatus comprises a filter-holder unit, where an optical filter that is pre-selected from a filter kit is bonded to an output end of a holder and is optically aligned in series with a pre-fabricated collimator subassembly. A second collimator subassembly is positioned at an output end of the filter-holder unit. A test light having the same wavelength as that at which the filter is designed to operate at is transmitted through the input collimator subassembly. The angle of incidence of the transmitted light is measured, and a location where the reflected beam portion of the test light hits the ferrule is determined. The measured distance/spacing data dictates where an output fiber pigtail should be axially positioned within the ferrule to achieve the measured angle of incidence for a particular filter transmitting light at that particular wavelength. The measured data is used to fabricate multiple groups of ferrules containing two or more fiber pigtails that are spaced apart to correspond to a particular filter operating at a particular wavelength has been tested. Each of the fabricated groups of ferrules are incorporated either into input or output collimator subassemblies and are segregated in separate collimator bins that are marked accordingly. The prefabricated collimator subassemblies are used to make various optical filtering devices having any desired number N of optical ports.