Mirror with thermally controlled radius of curvature

A radius of curvature controlled mirror comprising:

• a mirror having a front surface and a rear surface;
• a first flow of fluid applied to said mirror for cooling or heating said front surface;
• a second flow of fluid applied to said mirror for cooling or heating said rear surface;
• a controller for adjusting said first flow and adjusting said second flow in order to achieve a desired differential expansion between said front surface of said mirror and said rear surface of said mirror and thereby achieve a desired radius of curvature on said front surface of said mirror;
• said first flow of fluid includes a front cooling loop including a plurality of spiral-shaped front passageways in said mirror near said front surface and a fluid circulating through said front passageways;
• said second flow of fluid includes a rear cooling loop including a plurality of spiral-shaped rear passageways in said mirror near said rear surface and a fluid circulating through said rear passageways;
• said front cooling loop includes a front inlet port and a front outlet port;
• said rear cooling loop includes a rear inlet port and a rear outlet port;
• said fluid is at a constant temperature;
• and
• said mirror including a mirror body constructed of a material selected from the group consisting of silicon, silicon carbide, sapphire, and copper.