Parallel generation of multi-channel broadband chaos by a long-cavity FP laser with optical feedback

Parallel generation of multi-channel chaos is critical to applications, and the key challenge is the simultaneous generation of broadband chaos with multiple channels and low correlation. Here, we experimentally demonstrate a parallel broadband chaos generation scheme using a single long-active-cavity Fabry-Perot (LC-FP) semiconductor laser under optical feedback. The active-cavity length is designed to be 1500 μm, so the power spectrum of chaos is expanded and flattened by the mode-beating effect. The experimental result shows that all-mode chaos with a bandwidth of 33.76 GHz and a spectrum flatness of ±2.5 dB is obtained. Furthermore, eight-channel chaotic signals with bandwidth larger than 27 GHz and correlation coefficients smaller than 0.1 are parallelly generated using optical filtering, where the spectrum flatness is about ±4 dB.