ATTENUATOR SCREEN FOR CONTROLLED TRANSMISSION OF ELECTROMAGNETIC ENERGY TO AN OPTICAL SENSOR FOR STRAY LIGHT REDUCTION

摘要

An attenuator screen is positioned in front of the focusing optics of an optical sensor to reduce stray light from getting into the FOV of the optical sensor's opto-electronic detector. The attenuator screen comprises a 2-D array of substantially tubular elements whose inner surfaces are optically black within the detection band. Incident EM energy is allowed to pass through the screen up to a cut-off angle beyond which the energy is largely absorbed. The tubular elements may be tapered to provide an approximately flat transmission across the FOV.