Different from the RL systems, wher

Different from the RL systems, where the RSB phenomenon are frequently observed, bandgap laser shows weak disorder due to its self-assembled helical structure. Unexpectedly, based on the statistical study of the lasing spectra, the RSB can still be found when the bandgap laser operates at the threshold point. This RSB phenomenon is robust when the bandgap laser works at different temperatures and wavelengths. These results extend the scope of the feasibility of the spin-glass theory in the photonic field, which boost the understanding of the interplay between system disorder and lasing statistical behavior.