Holographic Diffraction Grating 5.5-inches wide by 5.5-feet long

This specially developed, high-efficiency diffraction grating is 100 times more efficient than acetate gratings. It can produce a spectrum bright enough for vivid classroom discussions even in rooms that do not darken. The shape of the grating surface produces a dispersion angle of 23.5 degrees and a groove separation of 19,050 lines per inch (750 lines per mm) for a wavelength of 550 nm. The sinusoidal shape of the grating surface places most of the light in the first order image. This shape is embossed in a polyester plastic. It can be used to make a spectrometer, a spectrum projector, or used with an overhead projector to produce a projected spectrum for demonstration purposes.

Some of the gratings come with four color filters: blue, red, green, and yellow. Used singly and in combination, you can demonstrate how light is affected by color filters, or how objects of a certain color appear when bathed in light of another color.