Optical fibre reflection coupler - couples light from one fibre to whole bundle of several whose characteristics differ

摘要

The device permits the flexibility is being adaptable to fibres of various spread angles (OMEGA) and diameters. By means of a movable optical element, the exit window of the smaller fibre can be matched to the end section of the fibre bundle. The optical system consists of a double element convex lens (L) which is able to move on an axis coincident with the fibre bundle (17) and a fixed mirror (18) which may be concave or plane according to the variation adopted. The optically flat fibrer bundle end plane (15) is the focal plane of the coupler and remains so to the second order of error for all lens movements. The beam re-emerging from the lens is parallel (though of different aperture) for all lens positions.