Abstract

It is well known that n-th order subharmonic oscillations (where n is integer) possess a fundamental property of having n possible and equally probable oscillation phases, each of which corresponding to the same oscillation amplitude.¹ It was demonstrated both theoretically and experimentally by this author² that very high order subharmonics can be excited in passive lump nonlinear systems driven by a sufficiently strong pumping signal. It was also shown that subharmonics can be generated by the optical parametric oscillator.³ In this paper we show that optical subharmonic oscillators may provide a novel kind of optical multistability - specifically, phase multistability of these oscillations, with the same amplitude for each steady state of the phase. This differs drastically from all presently known types of optical bistability, all of which are based on amplitude multistability. The new principle results in a unique property of the system which we call symmetry of the states: all the steady states of the system possess the same stability, noise, etc. characteristics and may be switched from one steady state to another by an external signal of the same small amplitude.

© 1985 Optical Society of America