A film includes a multilayer stack composed of unit cells having alternating
optical
layers of first and second diverse polymers A,B. The unit cells can consist essentially
of two (AB), four (2A1B2C1B), or six layers (7A1B1A7B1A1B). The layers form an
effective optical packet disposed between non-optical layers, the beginning and
ending optical layers of which are selected to control an optical figure of merit
such as spectral noise in the visible region. The arrangement of layers beginning
at one end of the effective optical packet defines a specific cyclic permutation
of the unit cell layer order, which provides a better figure of merit than an effective
optical packet of similar design but having a different cyclic permutation.
