Abstract

The laser with an intracavity saturable absorber is capable of exhibiting a wide variety of fluctuation properties. By using a discharge tube containing pure Ne gas as an absorber inside a He-Ne laser cavity, we succeeded in eliminating the third-order nonlinearity from the equation of motion for the slowly varying field amplitude of the laser. This was accomplished by adjusting the pressure and the discharge current in the absorber tube. The equation of motion for the scaled field amplitude in these conditions is where a is the so-called pump parameter and q(t) represents quantum noise. This equation describes the overdamped motion of a Brownian particle in a sextic potential well under the influence of quantum noise. Statistical properties of the laser were studied experimentally as the pump parameter was varied from negative values to positive values when the time evolution of the field amplitude was governed by the above equation.

© 1989 Optical Society of America