The same method is employed to gauge the distance between the lines on a diffraction grating.
Another way of obtaining considerable dispersion is by using a diffraction grating instead of a prism.
The prism of Newton and Fraunhofer is now displaced by the diffraction grating—ruled by Rowland 14,438 lines to the inch.
There are two ways open to us—one by glass prisms, and the other by a diffraction grating.
In some text-books it is told us that the diffraction grating gives us a dispersion which is in exact relation to the wave-length.
|diffraction grating |
A barrier consisting of alternately transparent and opaque stripes, through which radiation such as light is passed and projected onto a screen or other detection device. The interference patterns cast by the diffraction grating on the screen or detector can be analyzed to determine the frequency of the radiation. See also interferometer.