Patent ID: 7450299

Claim:
A broadband telescope, comprising: an oblique incidence optical system unit, which has a first reflecting mirror reflecting incident light at a first surface part made up of paraboloid of revolution, and a second reflecting mirror reflecting the light, which is reflected at said surface part of said first mirror, at a second surface part made up of hyperboloid of revolution; a normal incidence optical system unit, which has a third reflecting mirror that has a third surface part on which a multilayer film is formed, which continuously changes periodic lengths along the depth direction to reflect each light of a predetermined energy in a region extending from vacuum ultraviolet ray to extreme ultraviolet ray and has high reflectance due to total reflection over a visible light region, and reflects the incident light at the third surface part, and a fourth reflecting mirror that has a fourth surface part on which a multilayer film is formed, which continuously changes the periodic lengths along the depth direction corresponding to said third surface part of said third reflecting mirror to reflect each light of a predetermined energy in the region extending from vacuum ultraviolet ray to extreme ultraviolet ray and has high reflectance due to total reflection over the visible light region, and reflects the light, which is reflected at said third surface part of said third reflecting mirror, at the fourth surface part; and a detector to which reflected light reflected at said second surface part of the second reflecting mirror and light reflected at said fourth reflecting mirror are made incident and which spectrally detects the incident light.