Patent ID: 6462878
Filing Date: 2002-10-08
Classification: H01S

Abstract:
A method of constructing a mirror for a design frequency range, the design frequency range lying between a lower bound in the low microwave portion of an electromagnetic spectrum and an upper bound in the high X-ray portion of the spectrum, the mirror including a plurality of material layers being transparent to electromagnetic radiation in the design frequency range and having refractive indices that differ between individual layers in the plurality of layers, the differing refractive indices providing a spatial variation of optical thickness over the plurality of layers characterized by a plurality of sequential unit structures, each unit structure consisting of a central layer and two half-layers lying immediately adjacent to the central layer, the method comprising:specifying an initial design including: a double-chirped set of unit structures, wherein a central layer optical thickness varies over the double-chirped set such that a ratio of the central layer optical thickness to a sum of the optical thickness of two immediately adjacent half-layers varies monotonically over the double-chirped set, and a total optical thickness of each unit structure varies monotonically over the double-chirped set; and perturbing the initial design to account for frequency dependence of the refractive indices over the design frequency range by perturbing the optical thickness of layers in the initial design.