PURPOSE: Demonstrate continuous spectrum.

DESCRIPTION: The bright point source is used to provide a continuous white light spectrum. Light from the point source is focused by a condenser lens with iris and a 20 cm focal length cylindrical lens onto a slit. A 20 cm focal length convex lens then images the slit onto the screen through an equilateral prism. A lengthy video (144 Megabytes) describing the setup of this apparatus in some detail may be played by clicking here. You can see the shop drawings for the point source here.(Adobe PDF reader required)

SUGGESTIONS:

REFERENCES: (PIRA 5N30.10)Demonstration N1-02: PRISMATIC SPECTRUM OF WHITE LIGHT - INCANDESCENT, is a simpler version of this demonstration which remains already set up.

EQUIPMENT: Bright point source with condenser lens and iris, 20cm focal length cylindrical convex lens, slit, 20cm spherical convex lens, and flint glass prism.

SETUP TIME: 5 min.