Phase Statistics of Light/Photonic Wave Reflected from One-Dimensional Optical Disordered Media and Its Effects on Light Transport Properties
Round 1
Reviewer 1 Report
The manuscript ‘Phase statistics of light/photonic wave reflected from one-di-mensional optical disordered media and its effects on light transport properties’ reports the properties of reflected light from 1D Gaussian white-noise optical disordered media via simulating the Fokker-Planck (FP) equation. I think the author's approach to solve the weak disorder case is novel and well supported by analysis. I would be happy to recommend it for publication with no further need of necessary comment to add to it. I have a general comment on 1D vs 2D, whose answer is unnecessary to add in the main draft. Can the author comment on what approach and bottlenecks could be there to solve the 2D problem?
Author Response
Author’s Reply: We thank the Reviewer-1 for seeing the paper as novel and well supported by the analysis, and recommending the paper for publication.
Comments on 2D: The 2D problem may not easy to solve directly using the FP approach. However, there is an approach to solve 2D problem with N-channel disordered media. In this model, N-channels can be parallel to each other on a plane where every channel has the different disorder structure, and a constant hopping/mixing term between any two channels are allowed. Here a Langevin equation can be derived for Rnm (wave entering through m-th channel and reflected finally through n-th channel) (See Ref.[12] for details). No result is reported for the derivation of the FP equation for reflection for N-channel case.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This paper deals with the reflection of light by a one-dimensional disordered medium. The problem is treated numerically with a lot of significant results. I think that the present availability of powerful software tools like Mathematica and the like will make the numerical approach more and more important for problems where the analytical means are insufficient. This paper gives a good example of this kind of research.
The paper begins with a clear derivation of the equation to be used to face the problem of interest (a Fokker-Planck PDE). Then the author points out the parameters that rules the equation, and considers the limiting case of Random Phase Approximation where analytical solutions can be reached .
Next, the numerical attack is illustrated and the set of results obtained with it are presented for various disorder regimes.
A fairly complete discussion of the main results of the paper is presented and a comparison with previous findings available in the current literature is given.
I think the paper gives a significant contribution to the optics of disordered media, and should be accepted.
My only suggestion to the author is to add, in the introductory section, a pair of recent examples about the use of FP equation in optics. This would show that the math tool used in the paper has a wide range of occurrences in present optics. For example, the following two papers could be cited:
1] G. Osnabrugge et al, Generalized optical memory effect, Optica, 866 (2017).
2] D. M. Paganin and K. S. Morgan, X-ray Fokker-Planck equation for paraxial imaging, Scientific Reports, (2019) 9:17537,
but the author could choose different examples.
Author Response
Author’s Reply: We thank Reviewer-2 for his/her insightful comments and recommending the paper to accept for publication.
As suggested we have added the above two references as Refs: [30] and [31] in the revised manuscript. We have also added following sentence at the end in the revised manuscript:
“Other applications of PF approach in electromagnetic waves: PF approach has been applied in studying optical memory effect [30] and also for paraxial imaging using X-ray [31].
Author Response File: Author Response.pdf
