Revision Comments:
RESPONSE TO THE EDITOR
Dear Sir,
We appreciate the precise reviews of our paper made by the Reviewer and could only apologize for mistakes which mostly appear as a result of the simple lack of care while preparing the final version of our manuscript. We hope that proposed revisions have made our paper more accessible and will satisfy the Reviewer.
All significant changes we introduced are described in detail in response to the Reviewer – see below. Additionally, we decided to add single sentences in some paragraphs, which should give a better sense of its contents. In particular, we slightly expanded Conclusions.
We just have submitted our revised manuscript as well as the response via the online system.
Best regards,
RESPONSE TO THE REVIEWER
Reviewers' comments:
Reviewer #1: Polarization and phase are two intrinsic features of electromagnetic waves. The main motivation of this paper is to explore the possibilities of expressing the polarization vortices as superposition of homogeneous orthogonally polarized waves with purely phase vortices. Different polarization phase vortices can be obtained by using different sets of polarization parameters between two phase vortices. The proposed scheme has possible applications in the modulation of phase and polarization of light. There are two issues in the paper need to be elucidated further.
Thanking for the favorable review of our work, we would like to emphasize that all of the above remarks were considered during the preparation for publication of the article – but we were not sure what content we should conclude. It is always hard for the authors of the work to decide what else should be in the text and what is necessary to be repeated or what goes beyond the main purpose of the article.Taking into account the comments of the reviewer, we decided to extend our work a bit – however, we will omit some of the possibilities due to its limited subject matter and to have something to do in the future.
In this paper, the authors use a classical Mach-Zehnder interferometer to generate the polarization vortices although I do not think it is a highly efficient scheme. Stokes polarimeter can be used to an analysis the polarizations of the generated polarization vortices. However. I suggest the authors to retrieve polarization distributions of the generated polarized vortex beams [App. Phys. Lett. 104, 191110 (2014); Optics Letters 43, 3570 (2018)]. Moreover, it is difficult to evaluate the quality of the generated polarization vortices only from the
experimental results. Therefore, I suggest the authors add the comparison between theoretical results and experiment ones.
Yes, the use of Mach-Zehnder interferometer configuration and spiral phase plates is ineffective and already a bit outdated. We used such elements just because of the simplicity of the idea presented. Relevant references to the defects of such a system have been introduced in the text.
We have used the Stokes polarimeter to retrieve polarization distributions of the generated polarized vortex beams as it was mentioned at the beginning of Section 4. Nevertheless, initially we only used information about the parameters , , and to present their distributions and demonstrate the existence of polarization vortices. Guided by the suggestion of the reviewer, we decided to extend our work to Figure 2, where we presented the distribution of polarization states for two selected simulations of adding phase vortices. Further simulations would go beyond the scope of our article and it would be very risky to present appropriate distributions based on measurement data, considering not the best quality of the experiments performed.
It is known that the higher-order Poincare sphere has been proposed to describe the evolution of both the polarization and the phase. The north and south poles of the higher
order Poincare sphere represent the opposite spin states and orbital states. Unlike the previously reported cases, the orbital states on the hybrid-order Poincare sphere should not be confined to the above opposite condition and can be chosen arbitrarily. All vector vortex states can be mapped to the surface of the hybrid-order Poincare sphere [Physical Review A 91, 023801 (2015)]. I think that the proposed scheme in the present paper can be used to generate any desirable vector vortex states on higher-order Poincare sphere and hybrid-order Poincare sphere. To demonstrate the flexibility of their scheme, I suggest the authors add some discussion to illustrate it.
Once again, we emphasize the limited subject of our work and not the best performance of the experimental part. For this reason, we have only limited ourselves to the aforementioned presentation of Figure 2 and a few comments, inserted in the theoretical part and in the conclusions.
We hope that the changes made in the text as well as the awareness of the possible continuation of the topic will allow us to recognize our article worth publishing at Optics Communications.
Detailed description of changes:
1) Extension of information about the sense of scalar function [4]
2) Correction of information about the nature of beams, simulated and measured: in simulations we assumed a slight Gaussian curvature, the same for all cases, in the experiment the curvature changed significantly, depending on the spiral phase plates used – this was made at the beginning of Section 3 and repeated in Conclusions.
3) A new paragraph has been added together with a new Figure 2 (next drawings have been renumerated), showing the polarization distribution around selected polarizing vortices – just before the end of Section 3.
4) The discussion on the impact of measurement inaccuracies and the obtained results has been extended, with particular emphasis on the fact that they prevent a reliable presentation of polarization distributions in the diagram presented in Fig. 2. – at the end of Section 4. 5) Extended the conclusions of the information contained in the changes described in sections
2 and 4.
