A new chaos generator is described that produces chaotic fluctuations of th
e optical-path difference in a coherence modulator driven electrically by a
nonlinear delayed-feedback loop. Numerical simulations and experimental re
sults are reported. A closed branch of periodic solutions bounded by a forw
ard and a reverse Hopf bifurcation is observed for the first time, to our k
nowledge, for this type of nonlinear dynamical system. (C) 2001 Optical Soc
iety of America.