Corrections to "Theoretical investigation of a wavelength selective switch architecture based on a Bragg grating assisted MMIMI configuration"

In the above-named letter [ibid., vol. 11, pp. 839??841, July 1999] due to a sign error in the MMIMZI-solver, the published MMIMZI-output characteristic (see Fig.2) was incorrect, basically in terms of symmetry for the given design. This solver was also used in the program for the complete WSS-device simulation (see Figs. 1 and 3). The author apologizes for the mistake and presents corrections.