Observation of order and chaos in a nuclear spin-flip laser

Experimental observations and computer simulations of the nonlinear response are discussed for a single-mode, solid-state, nuclear spin-flip, ruby nuclear-magnetic-resonance (NMR) laser. A theoretical model is derived that is based on the classical Bloch equations and that demonstrates one-to-one correspondence to a homogeneously broadened, single-mode ring laser. Experimental evidence is presented for limit cycle behavior, sequences of subharmonic bifurcations, transitions to chaos, noisy bands, windows of regular behavior, intermittency, abrupt transitions between different basins of attraction, and hysteresis when a physical system parameter of the NMR laser is modulated at a low frequency. First experimental results are shown for a NMR laser with an external, detuned high-frequency signal below the injection-locking threshold. In this region, the output exhibits transitions from regular to chaotic oscillations and phase-locked spiking somewhat of the nature of what has been theoretically proposed for optical systems.