Synthesis of broadband retarders

Synthesis of broadband high-reflection multilayer retarders on transparent or absorbing substrate is considered. Broadband retarders at $45^{\circ}$ angle of incidence with $\pm90^{\circ}$, $160^{\circ}$, $180^{\circ}$ phase shift for the $\Delta\lambda/\lambda_0=7-14\%$ wavelength rang are represented.