We show that the well-known instability in actively mode-locked lasers with detuning between the resonator round-trip time and the modulator period exhibits a transition to turbulence analogous to fluid flow. We derive a universal normalized detuning of the laser that plays the same role as Reynolds number in fluid flow. This is the first time that the recently proposed theory for the onset of turbulence in hydrodynamics is verified in a system outside of hydrodynamics.

• Received 6 August 1998

DOI:https://doi.org/10.1103/PhysRevLett.82.4428