Superbunched random fiber laser

<title>Abstract</title> <p> Photon superbunching, with second-order coherence far beyond the Gaussian thermal limit, is a valuable resource for quantum optics and correlation-based imaging. However, existing sources often rely on fragile platforms, inefficient nonlinear conversion, or mechanically complex architectures. Here, we demonstrate the first highly stable, fully fiber-integrated superbunched random fiber laser that provides a broadly tunable source of giant photon bunching. We establish a cooperative linear–nonlinear mechanism in which Rayleigh-scattering-mediated diffusion provides distributed random feedback, while cascaded stimulated Brillouin scattering and quasi-phase-matched four-wave mixing amplify and redistribute stochastic intensity fluctuations across a spectral comb. This enables continuous tuning of g ⁽²⁾ (0) from approximately 1 to 28 via tailored modulation of linear diffusion strength and nonlinear coupling magnitude. Moreover, by combining photon-correlation measurements with Parisi-overlap analysis, we reveal an inverse correlation between disorder-induced photonic phase evolution and microscopic photon bunching, bridging macroscopic disordered-cavity dynamics and high-order photon statistics. Furthermore, we demonstrate that strongly superbunched light enables temporal ghost imaging with comparable reconstruction fidelity while requiring more than an order-of-magnitude fewer realizations than weakly bunched light. Together, these results establish a fiber-integrated route to engineering giant photon superbunching and high-order light statistics for correlation-based photonic technologies. </p>