Dielectric mirrors with anomalous angular dispersion of the phase of reflection

Multilayer dielectric mirrors, which make it possible to obtain an unconventional sign of the derivative of the phase of reflection Psi with respect to the angle of light incidence, partial derivative Psi/partial derivative theta(A) < 0, are described. The width of the domains where the derivative is negative is several degrees in theta(A) The mirrors have a D-a-DIV-D-b structure, where D-a and D-b are ordinary multilayers, and DIV is a nonquarter-wave layer separating them. D-a should have a higher reflection coefficient than D-b.