Frequency measurement and amplification of lidar echo signal based on optomechanical effects

Abstract

In this work, we have proposed a new scheme to measure the frequency of lidar echo signals by optomechanically induced transparency or amplification. Our calculation is based on the quantum Langevin equations and the mean-field approximation. The phenomenon that the transmission probabilities of echo signal light of lidar are sensitive to its frequency gives us a method to obtain the probe frequency. The expressions of the external force that keeps the system on the blue or red sidebands are offered, which is the necessary condition for our measurements. For the blue sideband, the process leads to the amplification of the echo signal light if the frequency of the pump field satisfies certain relations. For the red sideband, the echo signal light may be fully absorbed and at this time whose frequency can be obtained by a formula that has been proved in this work. In contrast to the conventional method, our method may have higher accuracy, and cavity optomechanics can amplify the signal under the condition of the blue sideband. Our scheme is based on the quantum theory, which may be easier to associate with quantum Fisher information that can give the highest precision.