E. K. A. ADVANCED PHYSICS LABORATORY PHYSICS 3081, 4051 THE He-Ne LASER AND OPTICAL RESONATORS

A laser produces electromagnetic radiation which is both spatially coherent and of narrow spectral width via a mechanism known as Light Amplification by Stimulated Emission of Radiation. The first working laser was developed in 1960 by Theodore Maiman at Hughes Research Laboratories. Since then laser technology has proliferated, with uses in industry, medicine, research, military and law enforcement, as well as in numerous commercial devices including CD and DVD players, laser pointers, bar code readers and printers. Lasing can be achieved in crystals such as rubies, in semiconductors, in chambers filled with dye, or in tubes filled with gas. In this experiment we will construct a simple cavity employing a tube filled with He and Ne gas excited by electrical discharge to create a visible laser in the red portion of the spectrum. He-Ne lasers are widely used in low-power laser applications because of their reliability and low cost.