Hyperuniform Disorder in Photonic Crystal Slabs With Intrinsic Non‐Hermiticity
Zeyu Zhang, Koorosh Sadri, Brian Gould, Mikael C. RechtsmanABSTRACT
Hyperuniform disorder is a type of correlated disorder characterized by vanishing spectral density at small wavevectors, making the configuration effectively homogeneous on long length scales. In photonics, hyperuniform disorder is promising for generating isotropic photonic pseudogaps and engineering photonic crystal waveguides. However, these studies are largely restricted to idealized lossless settings or settings in which loss arises from disorder‐induced scattering. In this work, light propagation in photonic crystal slabs with imposed hyperuniform disorder is investigated theoretically and numerically. The system is intrinsically non‐Hermitian due to radiative loss, with non‐Hermiticity appearing as a complex effective mass of a quadratic photonic band. A theoretical framework for disorder scattering is analytically derived in Hermitian and non‐Hermitian quadratic bands with real and complex effective masses, respectively. In contrast to the power law behavior observed in the Hermitian case (where is the hyperuniformity exponent), the scattering loss in the non‐Hermitian band is given by , where is a finite constant and the exponent . Our theoretical predictions are verified with tight‐binding and Finite‐Difference Time‐Domain simulations with realistic photonic crystal parameters based on recent experiments.