Voss Kenneth J, Gleason Arthur C R, Gordon Howard R, Kattawar George W, You Yu
Physics Department, University of Miami, Coral Gables, Fl 33146, USA.
Opt Express. 2011 Mar 28;19(7):5942-52. doi: 10.1364/OE.19.005942.
Neutral points are specific directions in the light field where the three Stokes parameters Q, U, V, and thus the degree of polarization simultaneously go to zero. We have made the first measurement of non-principal-plane neutral points in the upwelling light field in natural waters. These neutral points are located at approximately 40°- 80° nadir angle and between 120° - 160° azimuth to the sun which is well off of the principal plane. Calculations show that the neutral point positions are very sensitive to the balance in the incident light between the partially polarized skylight and the direct solar beam.
中性点是光场中的特定方向，在这些方向上，三个斯托克斯参数Q、U、V以及偏振度会同时变为零。我们首次测量了天然水体中向上传播光场中的非主平面中性点。这些中性点位于相对于天底约40° - 80°的角度以及相对于太阳方位角在120° - 160°之间，这与主平面相差很大。计算表明，中性点的位置对部分偏振的天空光和直接太阳光束之间的入射光平衡非常敏感。
