Four-channel orthogonally polarized interferometer for optical phase detection in turbulence

Abstract

A four-channel orthogonally-polarized interferometer for optical phase detection in turbulence is proposed. It is theoretically and experimentally demonstrated that the interferometer can be employed to detect phase fluctuations of an optical wave through atmospheric turbulence. In this framework, two portions of the optical field are captured, implemented polarization modulation, and performed interference. The orthogonally polarized interferogram is sent through four channels and the phase differences across the two apertures are measured in a single shot. The phase fluctuation and structure-function evaluated from a series of phase differences measured in a laboratory turbulence tank and in real atmospheric turbulence show good agreement with the theoretical prediction for atmospheric turbulence. Our method provided an important complement to Differential wavefront lidar under long-range, weak-light conditions which may be applied in real-time remote atmospheric sensing, and phase-based object transient dynamic tracking.