Tunable slow light in a double-cavity optomechanical system based on optomechanically and photothermally induced transparency

Abstract The optical response of double coupled optical cavities based on optomechanically and photothermally induced transparency (OMIT and PTIT) is reported in this research. A strong pump field and a weak probe field drive the left cavity, which couples a mechanical oscillator through the photothermal effect. The right cavity couples another mechanical oscillator through the radiation pressure. The double cavities couple with each other through photon tunneling. Double OMIT can be observed first when only the radiation pressure and the photon tunneling are considered in our system. Fano resonances with an asymmetric absorption profile are found under unequal frequency detunings. When the photothermal effect in the left cavity is considered, a new transparency window due to PTIT is generated. The system absorption dependent on the coupling strengths and frequency detunings is investigated in detail. Furthermore, we demonstrate that the PTIT can be adjusted and enhanced by the OMIT and Fano resonances. In addition, tunable slow-to-fast light by manipulating the photon tunneling is studied. The multimode interactions in our system may have various applications, such as in memory storage and the detection of tiny masses and small displacements.