Improve the sensitivity of an optomechanical sensor with the auxiliary mechanical oscillator Xiao-Yu Wang, Biao Xiong, Wen-Zhao Zhang and Ling Zhou Eur. Phys. J. D, 72 6 (2018) 117 Published online: 19 June 2018 DOI: 10.1140/epjd/e2018-90080-4