Stimulated emission divided by the input intensity: Substituting this definition into the prior equation, we find the general gain equation: In the special case where the input signal is small compared to the saturation intensity, in other words, then the general gain equation gives the small signal gain as or which is identical to the small signal gain equation (see above). For large input signals, where the gain approaches unity and the general gain equation approaches a linear asymptote: .3 Laser Fundamentals, William T. Silfvast Stimulated emission Stimulated emission is the process by which an incoming photon of a specific frequency can
Maser Maser A maser (, an acronym for "microwave amplification by stimulated emission of radiation") is a device that produces coherent electromagnetic waves through amplification by stimulated emission. The first maser was built by Charles H. Townes, James P. Gordon, and H. J. Zeiger at Columbia University in 1953. Townes, Nikolay Basov and Alexander Prokhorov were awarded the 1964 Nobel Prize in Physics for theoretical work leading to the maser. Masers are used as the timekeeping device in atomic clocks, and as extremely low-noise microwave amplifiers in radio telescopes and deep space spacecraft communication ground stations. Modern masers can be designed