Interreflection errors in Fourier transform spectroscopy: a preliminary appraisal

The presence of systematic ordinate errors in Fourier transform spectroscopy (FTS) is discussed, largely in terms of interreflection effects between the various interfaces of a two-beam interferometer and its adjacent optical components. Seven distinct categories of interreflection are specified and some consequences are noted. Certain types of optical filter are described which can be used diagnostically to distinguish between ordinate errors arising from interreflections and the intrinsic ordinate errors. The latter are those that remain when the interreflection effects have been removed by optical modifications. A strategy for achieving this is suggested. Finally, a theoretical model is being considered as a general way of handling a complicated problem. (C) 1999 The National Physical Laboratory. Published by Elsevier Science B.V. All rights reserved.