Patent ID: 6292604
Filing Date: 2001-09-18
Classification: G02B

Abstract:
A WDM filter comprising:a first optical fibre tube having two or more optical fibres securely held therein in a predetermined relationship;a second optical fibre tube having at least one optical fibre contained therein, the second optical fibre tube being optically aligned with one of the two or more optical fibres contained in the first optical fibre tube; an inwardly facing end face of the first fibre tube being slanted so as to reduce the effects of back reflections, the slanted end face having a slant of less than 15 degrees and greater than 2 degrees from a line orthogonal to a longitudinal axis of the optical fibre tube;collimating/focusing lenses disposed between the first and second optical fibre tubes, the collimating lens having an optical axis;an at least partially reflective optical filter disposed between the collimating/focusing lenses;end faces of the two or more optical fibres being fixed along a line at the end face of the slanted tube at locations equidistant from the longitudinal axis of the lens and at locations such that light launched from one of the at least two optical fibre end faces is collimated at a collimating location at or near the optical filter and such that collimated light at the collimating location is focused at another of the at least two optical fibre end faces, the line being substantially perpendicular to the longitudinal axis of the optical axis tube.