Phase control of squeezed state in double electromagnetically induced transparency system with a loop-transition structure

Highlights: • The property of a squeezed light passing through a double electromagnetically induced transparency system is investigated. • The squeezing can be preserved well under conditions of the ground-state decoherence rates. • The squeezing can be manipulated by the relative phase of the driving fields. - Abstract: We theoretically study the squeezed probe light passing through a double electromagnetically induced transparency (DEIT) system, in which a microwave field and two coupling lights drive a loop transition. It is shown that the output squeezing can be maintained in both two transparency windows of DEIT, and it can also be manipulated by the relative phase of the three driving fields. The influence of the intensity of applied fields and the optical depth of atoms on the squeezing is also investigated. This study offers possibilities to manipulate the squeezing propagation in atomic media by the phase of electromagnetic fields.