Abstract

We have analyzed an optical system in which two ring lasers are self-coupled. This means that the output of each laser is injected in the other laser. This problem goes back to a work of Spencer and Lamb¹ and was recently reinvestigated by Lawandy and Lee² to produce a Lorenz-type laser with a reduced effective threshold. We have followed the Spencer-Lamb approach and shown that quite a number of different situations can occur. The peculiarity of this system is that despite the fact that the atomic polarization can be adiabatically eliminated, there can remain an intense phase coupling. As a result one can observe periodic output, subharmonic bifurcation sequences, and various forms of chaos of the intensity. In a suitable domain of the control parameters such as the length of the two lasers and the back-coupling of each beam into the other laser, the system has no steady states at all and displays a behavior which is similar to that of a good cavity laser with modulated losses. Therefore, all the variety of multistage periodic and chaotic solutions found in the good cavity laser with modulated losses is recovered in this system.

© 1988 Optical Society of America