A numerical technique for analyzing multireflector optical resonators with an arbitrarily large number of mirrors is applied to the design of ripple-free, flat-top bandpass filters. The algorithm determines unique values for the mirror reflectances Rj, j= 1, ... N, subject to a constraint on a contradirectional coupling strength parameter Z defined as Z= Sum^N j=1 zeta j with zeta j=tanh^-1(sqrt Rj) . The method is applied to the design of resonators with N as high as 12. Transmittance and dispersion spectra are presented for two cases that represent relatively weak and relatively strong contradirectional coupling. These spectra illustrate that, for a fixed -20-dB width of the transmittance spectrum, the -3-dB spectral widths increase monotonically with N, while the central portion of the group refractive-index spectrum becomes flatter and wider as N increases. These designs are compared with those obtained using a Chebyshev formula to determine the mirror reflectances. Application of these multireflector resonators as bandpass filters, slow-wave electrooptic modulators, and nonlinear optical devices are discussed.
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