Optical system for a multidetector array spectrograph

Claim 1

An apparatus for the measurement of light intensity by wavelength comprising: a concave grating for the dispersion and focusing of light by wavelength; said concave grating having a preferred plane to disperse light and having a normal lying in said preferred plane relative to which angles may be defined as rotations around a rotation point located at the intersection of said normal and the surface of said grating, detector means optically coupled to said concave grating for the conversion of light energy to electrical energy indicative of said light intensity; said detector means comprising a plurality of light sensitive elements, said detector means being positioned such that said light sensitive elements are present at or between angles of 8.3 and 14.4 degrees from the grating normal, a first port for entrance of light to the apparatus; the center of said first port being at a specific first angle chosen to be between -0.3 and -5.4 degrees from the grating normal, the location of said first port along a line defined by said chosen first angle and said rotation point selected so as to obtain optimum focus of light entering at said first port at said detector means by said grating, and a second port for entrance of light to the apparatus; the center of said second port being at a specific second angle chosen to be between -0.3 and -5.4 degrees from the grating normal, the location of said second port along a line defined by said chosen second angle and said rotation point selected so as to obtain optimum focus of light entering at said second port at said detector means by said grating.

Claim 2

An apparatus for the measurement of light intensity by wavelength comprising: a concave grating for the dispersion and focusing of light by wavelength; said concave grating having a preferred plane to disperse light and having a normal lying in said preferred plane relative to which angles may be defined as rotations around a rotation point located at the intersection of said normal and the surface of said grating, detector means optically coupled to said concave grating for the conversion of light energy to electrical energy indicative of said light intensity; said detector means comprising a plurality of light sensitive elements, said detector means being positioned such that said light sensitive elements are present at or between angles of 8.3 and 14.4 degrees from the grating normal, a first port for entrance of light to the apparatus; the center of said first port being at a specific first angle chosen to be between -0.3 and -5.4 degrees from the grating normal, the location of said first port along a line defined by said chosen first angle and said rotation point selected so as to obtain optimum focus of light entering at said first port at said detector means by said grating, and a second port for entrance of light to the apparatus; the center of said second port being at a specific second angle chosen to be between -0.3 and -5.4 degrees from the grating normal, the location of said second port along a line defined by said chosen second angle and said rotation point selected so as to obtain optimum focus of light entering at said second port at said detector means by said grating.