The coefficients for the expansion of a plane wave in terms of the eigenstates (modes) of a Selfoc® fiber are derived. This result is used as the basis for a suggestion for a new optical fiber whose spectral response could be any one of the functions used extensively in colorimetric instrumentation.
P. M. Tannenbaum, "Expansion of a plane wave in terms of Laguerre-gaussian functions and the spectral response of Selfocs®," J. Opt. Soc. Am. 65, 56-58 (1975)