Dynamics of non-linear feedback systems with short time-delays

We report a study of optical systems with delayed non-linear feedback when the ratio T/tau of the time-delay T and the response time tau of the system ranges from 10 to 0.01. Results of numerical simulations and experiments i ncluding the statistics, the bifurcation diagrams, the power-spectra and th e correlation parameters are reported and show that the dynamics evolves fr om high-dimensional chaos to quasi-periodic oscillations and multistability . The frequency of the P-2 regime is shown to differ from 1/2T when T/tau d ecreases. (C) 2001 Published by Elsevier Science B.V.