Optomechanical force sensor in a non-Markovian regime

An optomechanical force sensor for a mechanical oscillator in a non-Markovian environment is presented. By performing homodyne detection, we obtain a general expression for the output signal. It is shown that the weak force detection is sensitive to the non-Markovian environment. The additional noise can be reduced and the mechanical sensitivity can be obviously amplified compared to the Markovian condition even in resolved sideband regimes without using assistant systems or squeezing. Our results provide a promising platform for improving the sensitivity of weak-force ultrasensitive detection.