Patent ID: 8773659

Claim:
A spectrograph comprising: a housing having a light entrance assembly for receiving an incoming beam of light from a source point of light; A focal plane array detector; at least one optical element having a collimating portion arranged for collimating said incoming beam of light to produce a collimated beam, and a dispersing portion for dispersing said collimated beam of light into a dispersed light beam comprising a plurality of wavelengths; a focusing optical element having a concave surface arranged for focusing said dispersed light beam onto said focal plane array detector, wherein said focusing optical element has a radius of curvature and is located a distance equal to said radius of curvature from said dispersing portion, and wherein said focusing optical element comprises an aspheric departure from said concave surface adapted to add or subtract aberrations; and at least one aberration-correcting element positioned within said housing for receiving and reflecting light, wherein said aberration correcting element includes an aspheric surface adapted to add or subtract aberrations.