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

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. • We have developed a four-channel orthogonally polarized interferometer designed for ultra-weak light detection over long propagation paths. • Our interferometer enables optical phase detection in a single shot. Both theoretically and experimentally, we have demonstrated its capability to detect phase fluctuations of an optical wave in the presence of atmospheric turbulence. • Over a 1.1 km propagation path, we successfully measured phase fluctuations. The magnitude and variation of Fried's parameter measured consistent with those obtained by DIMM. Furthermore, our method allows for faster and more accurate phase detection. [ABSTRACT FROM AUTHOR]