Self-pulsing instability in the cascaded optical parametric oscillator

The temporal dynamics of a mltiphoton doubly-resonant optical parametric oscillator (OPO), in which a notresonated pump field at frequency 4omega is down-converted into photons at frequencies 2omega and omega through the two cascaded degenerate processes 4omega --> 2omega + 2omega and 2omega --> omega + omega, is theoretically investigated. A low-threshold self-pulsing instability is identified and analyzed both analytically and numerically. When the field at frequency omega is tuned at exact resonance with a cavity mode, in the self-pulsing regime the OPO emits a periodic train or bright pulses for the field at frequency omega and of dark pulses for the field at frequency 2omega. Period doubling and transition to chaos is observed for detuned operation of the field at frequency omega. (C) 2002 Published by Elsevier Science B.V.