Abstract

A semiconductor laser whose cavity contains a saturable absorber can exhibit a wide variety of instabilities including self-sustained pulsations of the output radiation for a constant driving current. We have investigated the nonlinear dynamics of a self-oscillatory semiconductor laser whose pumping current is modulated at a frequency f_m close to the free oscillation frequency f₀ or one of its harmonics. As the modulation depth is increased we observe frequency locking, intermittency, and chaotic behavior in the output radiation. Our observations agree well with numerical simulations based on the rate equations for a laser with a fast saturable absorber.

© 1985 Optical Society of America