Effects of the atmospheric phase fluctuation on long-distance measurement

Optical phase noise from atmospheric fluctuations and its impact on optical time-frequency transfer

“…Indeed, while some experiments have confirmed the Kolmogorov f −8/3 scaling, a number of experiments have also found shallower power-law scaling for Fourier frequencies as low as 1 mHz [8,9,11,12,14,15,20,44]. In our work, we have extended the range of Fourier frequencies probed down to 100 μHz.…”

“…II, where an assumed spatial scaling of the turbulence is mapped to the frequency domain through Taylor's frozen-turbulence hypothesis. In this picture, the optical phase PSD would exhibit four distinct regions: (1) a very steep roll-off at high frequencies, f > V /l 0 , corresponding to the dissipative region (or actually sooner due [9] Dual-beam laser 70 m 200 mHz-500 Hz 0 No evidence b interferometer [11] Dual-beam laser interferometer 100 m 100 mHz-200 Hz 0 No evidence c at 632 nm [20] Laser interferometer 11 m 100 mHz-100 Hz -0.2 None (requires at 632 nm L 0 >11 m) [20] Stellar interferometry NA 10 mHz-5 Hz -0.43 Tens of meters [12] Stellar interferometry NA 1 mHz-100 Hz -0. [10].…”

“…Specifically, the derivation makes use of Taylor's hypothesis, which assumes that the turbulence spatial structure is frozen, so that the only time dependence arises from the wind [7]. Other results in the literature have also found shallower power-law scaling and an absence of a low-frequency roll-off [8][9][10][11][12][13][14][15], although none have probed the atmospheric optical phase noise on as long a time scale. Nevertheless, the power-law scaling observed here over a full five orders of magnitude is a strikingly simple result particularly when considered in the light of the full complexity of turbulence and weather.…”

Wide range distance measurement over 50 km based on highly sensitive detection of the two-photon absorption photocurrent from a Si-APD

“…Some typical systems are based on time-of-flight measurement [1,2]. Other systems use phase detection of intensity-modulated optical signals [3,4]. Optical frequency combs are also applied to precision distance measurement [5].…”