| Astrophysics (Index) | About |
A cross dispersion spectrograph uses two stages to increase its spectral resolution: first, an echelle grating, which separates the spectrum but with some overlap, and then crosswise to it (fairly close to 90 degrees, I believe) an additional disperser, which could be a prism or a series of prisms. The result is a set of nearly parallel "bars" showing the light and dark portions of the spectrum, each bar showing a part of the spectrum, with some overlap with the adjacent bars. The rectangle encompassing these can be recorded with film or a CCD. Examples: