Ultrafast real-time parallel random bit generation based on a directly modulated chaotic semiconductor laser diode

Modern cryptographic systems demand ultrahigh-speed physical random bit generators (RBGs) capable of Tb/s operation, yet conventional approaches combining optical chaos with electronic processing face fundamental bandwidth limitations and time delay signature (TDS) vulnerabilities. Here, we propose a monolithic semiconductor laser diode-based RGB architecture capable of achieving real-time parallel random bit extraction through chaotic comb self-generation and pulse amplitude chaos generation under direct modulation. Solitary laser diodes produce chaotic signals without TDS, thereby eliminating the requirement for optical feedback or digital post-processing. Multi-channel chaotic waveforms with a channel effective bandwidth of 10.3 GHz and ps-level temporal jitter were successfully generated. Single-channel 10 Gb/s real-time random bit verified by NIST SP800-22 is achieved. Furthermore, parallel wavelength-division multiplexing enables scalable operation at a data rate of 50 Gb/s. Since chaotic comb self-generation comprising 173 channels within a 100 nm wavelength range using a solitary laser diode have been demonstrated in our previous work, it conservatively estimates the potential for Tb/s capacity through spatiotemporal chaos multiplexing in integrated III-V photonic circuits. This work establishes a new paradigm for chip-scale ultrahigh-speed RBGs, overcoming the electronic bandwidth barrier while maintaining unpredictability. This technology opens avenues for large-scale integrated secure communication systems and stochastic computing architectures.