Synchronized generation of ultranarrow superradiant lasers with stable frequency
Phys. Rev. A 113, 053715 – Published 13 May, 2026
DOI: https://doi.org/10.1103/wfbq-ssbw
Abstract
Superradiant lasers are promising candidates for ultrastable atomic clocks, but their frequency stability is fundamentally limited by cavity-pulling effects induced by cavity detuning. Here we propose a scheme to synchronously generate two ultranarrow superradiant lasers with stable frequencies by coupling two cavity modes to an atomic ensemble. We show that destructive interference between the cavity modes and the atomic ensemble suppresses the collective frequency shift. This mechanism enables the superradiant laser to operate precisely at the stable atomic transition frequency, rendering it insensitive to cavity detuning. As the cavity detuning increases, the linewidths of the superradiant lasers are reduced by approximately two orders of magnitude, reaching the microhertz regime under realistic conditions. Meanwhile, increasing the atom number enhances the emission intensity while preserving the ultranarrow linewidth. We further analyze how the emission frequencies and intensities of the two cavity modes depend on the coupling strengths and cavity detunings and we identify the parameter conditions required to generate ultranarrow superradiant lasers whose frequencies are locked to the atomic transition frequency. Our work may play an important role in advancing atomic clocks and a broad range of precision-metrology applications.
