Optical Heterodyne Generation of High-Dimensional and Broadband White Chaos

Physical chaos is a fascinating prospect for high-speed data security by\nserving as a masking carrier or a key source, but suffers from a colored\nspectrum that divulges system's intrinsic oscillations and degrades randomness.\nHere, we demonstrate that physical chaos with a white spectrum can be achieved\nby the optical heterodyning of two delayed-feedback lasers. A white chaotic\nspectrum with 1-dB fluctuation in a band of 11 GHz is experimentally obtained.\nThe white chaos also has a perfect delta-like autocorrelation function and a\nhigh dimensionality of greater than 10, which makes chaos reconstruction\nextremely difficult and thus improves security.\n