Patent ID: 7936454

Claim:
A portable hand-held spectrograph, comprising: a diffraction grating configured to receive light from a radiation source; a dispersive prism in optical communication with the diffraction grating; a primary concave mirror configured to reflect light traversing the dispersive prism; a spheroidal convex secondary mirror configured to receive light reflected by the primary mirror; a tertiary concave mirror in radiative communication with the secondary mirror, wherein the primary mirror, the secondary mirror, and the tertiary mirror form a three-mirror anastigmat (“TMA”) with a common vertex axis; and an entrance aperture configured to receive light from the radiation source, and a collimating mirror configured to reflect said light in a collimated pattern towards an aperture stop and deliver said light to the diffraction grating, the collimating mirror and the entrance aperture being disposed in an interchangeable module, the entrance aperture being located along a parent optical axis of the collimating mirror, wherein the diffraction grating is configured for receiving and diffracting light that has passed through the aperture stop into a plurality of beams dispersed by wavelength and directed onto the dispersive prism, and wherein the portable spectrograph can detect light at wavelengths between 150 nm and 1.1 μm.