Mode Shift of a Thin-Film F-P Cavity Grown with ICPCVD

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In the manuscript, the authors designed a multilayer periodically structured optical film containing Fabry-Perot cavity with 9 pairs of SiN/SiO2 dielectrics.  The effects of polarization of incident light, incident angle and ambient temperature on the cavity mode are investigated. The reviewer has the following comments and suggestions:

 

1. How to calculate the Q value? This should be clearly indicated in the manuscript.   

 

2. “ It is evident that the FWHM slightly increases as the temperature rises, while the Q value shows a slight decrease.”. Please explain this in more detail.

 

3. Red shifts are observed for the center wavelength in the reflection spectra in Figs. 3e and 3f. Please explain this red shifts.

 

4. “Unlike the angle of incidence, variations in temperature have a negligible impact on the chromaticity coordinates of the film.”. Please explain this in more detail.

 

5. The reflectance spectra were measured and simulated within the incident angle range from 0° to 60°, why not 0° to 90°?

 

6. 9 pairs of SiN/SiO2 dielectrics are used in the proposed filter in this manuscript. What is the effect of the number of pairs of SiN/SiO2 dielectrics on the reflectance spectra, FWHM, and Q-value?

 

7. “In addition, when the optical films are exposed to p/s polarized light at different angles of incidence, the cavity mode of the film undergoes a blue shift... ”. Why?

Comments on the Quality of English Language

Moderate editing of English language required. 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

To sum up, the manuscript can be improved. The results sound sensitive to me and I believe they could be of certain interest for an specialized reader. However, as this is not a technical report but a scientific paper the authors should make an effort to improve the quality of the manuscript, currently quite poor.

I will mention three examples but all the manuscript is full of incorrect sentences, mainly when dealing with fundamentals:

 

1) The authors use an stochastic function to account for what the call "random errors in film thickness", which I undestood is the tolerancy on the growing parameters. From the results (as they do not explain it propertly), I believe that this stochastic function has maximum and minimum bounds and homogenour probability all over around this bounds. However, this function will be modulated in a real case (e.g. a Gaussian or Student's T)

 

 

2) Dn/DT is exactly a temperature coeficient.

3) The human retina contain three types of photoreceptors which feed the yellow-blue channel, the red-green channel and the achromatic chanel. Other point is that the RGB basis can cover most of stimuli generated in the human eye.

 

 

Comments on the Quality of English Language

In general de language in the manuscript can be understood, however, it is full of unaccuracies, even in the subsection topics.

For example, I would not say "Random film thickness error analysis" or "To understand the discrepancy between measured and designed values" or ". Tilted incidence of dielectric films "

There ara many of those. I strongly recommend the proofreading by a native speaker.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

Correspondence of the title to the content of the manuscript: The content of the text of the manuscript corresponds to the title.

 

Briefly review: As I understand it, the work is devoted to manufacturing of a high-quality Fabry-Perot filter by ICPCVD method on a relatively large 8" substrate. Authors used standard calculation methods. The errors of the experimental results are analyzed. The dependences of the displacement of the reflection spectra on the angle of incidence and temperature are also investigated.

 

Actuality of investigation:

I think the research is relevant, but not in the context that corresponds to the title of the article. It seems to me that the relevance should be more related to the technology of production of a multilayer coating.

 

Science novelity: In my opinion, the article has a technical novelty associated with the development of manufacturing technology for a high-quality Fabry-Perot interferometer. At the same time, the technology includes the selection and control of the parameters of materials by the ICPCVD method.

 

Reliability of results:

As it seemed to me, the reliability of the results is sufficient. 

 

Other remarks:

1. What are the estimated reflection coefficients of the interferometer mirrors? Or what kind of finess of the interference fringes and free spectral range of interferometer? It is necessary to provide an estimated values.

2. Line 192: TMM is not explaned.

3. The uniformity of the layers applied to the substrate is unclear. The spectrum was measured at one point of the substrate, what kind of spectrum will be in another, sufficiently remote place of the substrate, for example from the other edge? It is necessary to add an explanation about the uniformity of the thickness of the films.

4. Figure 3(c): There is no FWHM dimension on the vertical axis.

5. Figure 3(e, f): refractive index should be replaced by reflection.

6. In the introduction, the authors point out the possible application of the structures they have produced, in particular, the selection of laser modes. It seems to me that it is quite difficult to apply their structures on a bulk substrate to select laser modes and at the same time to adjust the wavelength, since it is necessary to change the angle of incidence and reflection from the mirror, which will extremely complicate the structure of the resonator. At the moment, the advanced method of selection and adjustment of the generation wavelength is integrated optical filters based on the Vernier effect, which, in fact, are structures similar to Fabry-Perot multiplex interferometers.

7. The specified application of the structure as a temperature sensor is a well-known method. It is similar to the methods of fiber Bragg gratings, but obviously loses to it in compactness.

8. Despite the fact that the authors have done quite a lot of good technical work, as I think, the title of the article was chosen unsuccessfully, since it has long been a well-known fact that the blue shift of the spectrum of a multilayer coating with an inclined incidence of light and red when heated.

9. For me, a much more interesting technical point of view would be, for example, a report on the spectral properties of a mirror along the surface.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Since all the issues are well addressed, I think this manuscript can be accepted.

Comments on the Quality of English Language

Minor editing of English language required

Reviewer 3 Report

Comments and Suggestions for Authors

I think the authors have made some positive adjustments to the text, so I think publication is possible.