Light Trapping Arrangement
Original Publication Date: 1986-Dec-01
Included in the Prior Art Database: 2005-Mar-09
Unwanted or spurious internal reflection in an optical beam splitter can be eliminated by incorporating an optical absorbing element onto the reflecting surface. The optical absorbing element is index matched and mated to the reflecting surface so that any light incident on the surface passes into the absorbing material and is optically lost. In the optical arrangement shown in Fig. 1, unwanted or spurious reflections can arise at the interface AB. These reflections can be particularly annoying if that which is to be observed at the interface BC reflects or scatters light weakly. While an anti-reflection coating can be applied to the surface AB, this coating only reduces the reflection.