The revised paper still contains some technical issues which may affect the interpretation of the experimental results.
(1) Page 1 in the point-to-point response to Referee #2.
AC: "Before starting the measurements, the polarization of the water SHG signal was analyzed and found to have the expected maxima at S and P polarizations. (Has been mentioned in the revised version, P. 3, L. 35-37)"
Reviewer 2: It is not clear what are “the expected maxima at S and P polarizations.” Because mica is birefringent, the polarizations of the incident beam and the output SHG may be rotated. This effect is related to the incident plane, the incident angle, and the thickness of the individual mica used in the experiments.
(2) Page 4 in the point-to-point response to Referee #2.
AC: “The border between a film at the solid-air interface and a bulk (ice or water) was defined experimentally by the point where the intensity of a TIR reflected light from the solid-air interface drops due to the violation of TIR condition when the refractive index of the contact medium changes drastically from that of air (na=1) to one of those of water or ice (nw or i > 1.3).”
Reviewer 2: If this is the experimental setup, the SHG drop in Figure 4 is highly related to the Fresnel factors calculated by the author. As the Fresnel factors depend on the polarization of light, the birefringent property of mica has to be considered or ruled out. Data before and after the Fresnel factor correction should be shown in Figure 4. |