Using a super-luminescent emitting diode (SLED) source with a linewidth of more than 60 nm, we realize truly random number generation up to 100 Gb s −1 by directly measuring the intensity noise, which originates from the fluctuations of spontaneous emissions. Furthermore, we propose a post-processing method in an over-sampling scheme by eliminating the correlation between adjacent samples, and achieve an ultra-high truly random number generation rate of 1.6 Tb s −1 . The randomness of the generated bit stream is verified using standard statistical test suites (Diehard and NIST-STS), and evaluated using a three-standard-deviation criterion and Shannon entropy estimation.
Phase randomization is essential for the security of practical decoy-state quantum key distribution (QKD) systems. Commonly, implementations rely on laser sources which are either actively phase-randomized, or gain-switched. However, at high repetition rates these show correlations, which can ultimately compromise security and performance. We present a 1.25 GHz phase-randomized QKD source based on a super-luminescent light emitting diode (SLED) operating in the C-band as a compact and cost-effective alternative. The source generates
∼100 ps optical pulses with
400 ps pulse-to-pulse separation, compatible with high-speed time-bin encoding. Interferometric measurements demonstrate
>99% visibility between adjacent time bins, confirming strong first-order coherence within the same quantum signals, while the spontaneous-emission-driven nature of the SLED ensures intrinsic global phase randomization between adjacent signals. This work establishes a scalable SLED-based platform for high-speed prepare-and-measure QKD systems.