Mirror for high-intensity ultraviolet light beam

A mirror for reflecting high-intensity ultraviolet light, comprising:

• a substrate;
• a dielectric film comprising alternating layers of high- and low-refractive index material:
• and
• a metallic film situated between the substrate and the dielectric film, wherein the dielectric film comprises a first group of alternating thin-film layers, a second group of alternating thin-film layers, and a bonding layer situated between the first and second groups.

A mirror for reflecting high-intensity ultraviolet light, comprising:

• a substrate;
• a dielectric film comprising alternating layers of high- and low-refractive index material;
• and
• a metallic film situated between the substrate and the dielectric film, wherein the dielectric film comprises n groups of alternating thin-film layers, the groups being separated by bonding layers, and the alternating layers having film compositions that are defined by:
• H.sub.1 (L.sub.1 H.sub.1).sup.a1 /L.sub.1 '/H.sub.2 (L.sub.2 H.sub.2).sup.a2 / . . . /L.sub.n-1 '/H.sub.n (L.sub.n H.sub.n).sup.an
• wherein H.sub.1 through H.sub.n denote high-refractive index layers in a first group through an nth group;
• L.sub.1 through L.sub.n denote low-refractive index layers in the first group through the nth group;
• L.sub.1 ' through L.sub.n-1 ' denote bonding layers in the first group through the (n-1)th group;
• and a1 through an denote coefficients of repetition of the alternating layers.

A mirror for an excimer laser, comprising:

• (a) a substrate;
• (b) a dielectric film comprising alternating layers of high- and low-refractive index material;
• (c) a metallic film situated between the substrate and the dielectric film;
• (d) each of the alternating layers having a refractive index and an optical-film thickness;
• (e) the alternating layers having a film composition defined as
• n.sub.1L (n.sub.1H .multidot.n.sub.2L).sup.i .multidot.n.sub.1H .multidot.n.sub.1L .multidot.n.sub.2H (n.sub.3L .multidot.n.sub.3H).sup.i .multidot.n.sub.3L .multidot.n.sub.2L, wherein n.sub.1L, n.sub.2L, and n.sub.3L denote refractive indices of the low-refractive index layers;
• n.sub.1H, n.sub.2H, and n.sub.3H denote refractive indices of the high-refractive index layers;
• and i and j are each independently a positive integer denoting a respective coefficient of repetition for the alternating layers;
• and
• (f) the alternating layers having a relationship of optical-film thicknesses defined as
• 2n.sub.1L .multidot.d.sub.1L =n.sub.1H .multidot.d.sub.1H =n.sub.2L .multidot.d.sub.2L
• 2n.sub.2H .multidot.d.sub.2H =n.sub.3L .multidot.d.sub.3L =n.sub.3H .multidot.d.sub.3H
• wherein n.sub.1L .multidot.d.sub.1L, n.sub.1H .multidot.d.sub.1H, n.sub.2L .multidot.d.sub.2L, n.sub.2H .multidot.d.sub.2H, n.sub.3L .multidot.d.sub.3L, and n.sub.3H .multidot.d.sub.3H denote optical-film thicknesses of film structures n.sub.1L, n.sub.1H, n.sub.2L, n.sub.2H, n.sub.3L, and n.sub.3H, respectively.

A mirror for an excimer laser, comprising:

• (a) a substrate;
• (b) a dielectric film comprising alternating layers of high- and low-refractive index material;
• (c) a metallic film situated between the substrate and the dielectric film;
• (d) each of the alternating layers having a refractive index and an optical-film thickness;
• (e) the dielectric film comprising groups of alternating thin-film layers, each group separated from adjacent groups by a bonding layer, the film compositions of the alternating layers being defined by
• H.sub.1 (L.sub.1 H.sub.1).sup.a1 /L.sub.1 '/H.sub.2 (L.sub.2 H.sub.2).sup.a2 / . . . /L.sub.n-1 '/H.sub.n (L.sub.n H.sub.n).sup.an
• wherein H.sub.1 through H.sub.n denote high-refractive index layers in a first group through an nth group;
• L.sub.1 through L.sub.n denote low-refractive index layers in the first group through the nth group;
• L.sub.1 ' through L.sub.n-1 ' denote bonding layers in the first group through the (n-1)th group;
• a1 through an denote coefficients of repetition of the alternating layers;
• wherein each of the alternating layers has an optical-film thickness defined by
• X.sub.1 >X.sub.2 >
• . . . >X.sub.n
• Y.sub.1 >Y.sub.2 >
• . . . >Y.sub.n-1
• wherein X.sub.1 through X.sub.n denote optical-film thicknesses of the thin-film layers in the first group through the nth group;
• and Y.sub.1 through Y.sub.n-1 denote optical-film thicknesses of the first bonding layer through the (n-1)th-bonding layer.