Alternative Beam Splitter/Compensator Configurations for Reduction of Multiple Reflections in Imaging Fourier Transform Spectrometers

University of Utah

Eight alternative beam splitter/compensator configurations for use in imaging infrared Fourier transform spectrometers are presented The objective is to identify one or more configurations that may reduce multiple reflection problems in imaging Fourier transform spectrometers. The alternative configurations include: (1) dual slab with antireflection coatings, (2) dual slab at angles other than 45 ~ (3) dual slab with no air gap, (4) dual slab with widened air gap, (5) square 45 o cube, (6) hexagonal 60 ° cube, (7) vertically stacked parallel slab, and (8) vertically stacked non-parallel slab. A description and brief analysis of each alternative configuration is included The conclusion is that the dual slab with widened air gap configuration exhibits the best potential for reducing multiple reflections in imaging Fourier transform spectrometers.