Magnetically induced perfect absorption and slow light trapping in a double-cavity structure with strontium atoms

Photon manipulation using quantum interference is crucial for understanding the physical meaning of optical phenomena and promoting photonic quantum technologies. Here, two fundamentally optical phenomena, including coherent perfect absorption (CPA) and slow light trapping, are proposed simultaneously in a double-cavity structure with strontium atoms. When two counterpropagating probe fields are injected into the coupled atom-cavity system, we demonstrate that double-cavity-mediated interference assisted by the atomic Zeeman effect can be utilized to control multiple mode splitting in the transmission light. According to the analytical CPA criterion, we report that these splitting modes in the output spectra can be completely absorbed, forming multiple perfect or nearly perfect absorption. More importantly, we illustrate that sizable intracavity field localization can be found at the multiple CPA points, as an amount of system energy stores in the intracavity fields and the atomic excited states. In this case, the dispersion property of the system enables the localized intracavity fields to operate in the long-lived slow-light regime, whose group delay is tuned to be in the order of microseconds.