Optical Properties of Tungsten: A Parametric Study to Characterize the Role of Roughness, Surface Composition and Temperature
, Laurent Gallais 2, Régis Bisson 1 and Marco Minissale 1,*
Round 1
Reviewer 1 Report
The manuscript refers to the optical characterization of five W samples annealed at different temperatures and different roughness caused by chemical etching. By measuring the surface rms roughness and their optical reflectivity, authors affirm that changes on the reflectivity are due to the changes of the chemical composition of W when samples are annealed.
The manuscript is interesting but some details require to be attended before publication:
1. M1 and M2 items require to be included in the caption of Figure 1.
2. Some typical obtained AFM images of the surface of the W samples (annealed and not annealed) requires to be included for clarification of the rms-roughness reported.
3. The sentence (lines 175-178): “We have found similar relative reflectivity variation for the five samples as a function of wavelength with values ranging from 5% in the case of W1 to 10% for W2. However, we did not observe any irreversible evolution of the reflectivity after the second and third annealing”, is not clear and requires to be clarified.
4. Line 214. Why authors affirm that sample W1 “presents a lower reflectivity increase after the first laser annealing”. More explanation is required
5. Ref. [18] has wrong data at the final.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The authors report on the effect of roughness and annealing temperatures on reflectivity of W samples. They comment on two different effects that can induce change, namely, surface roughness and elemental composition. While there are some interesing conclusions, they selectively choose to present date on some samples withouth explaining why was this specific sample/condition chosen. Additional figures need to be added in the Supplementary information (SI) and commented on in the main manuscript.
Some more specific comments;
1. My first questionafter looking at the paper was going to be, why is there no microscopy study. Then i saw that there is a Table 1 with data from AFM and CM measurements, but the paper would benefit a lot if there is a selection of figures (one per sample) that can go at least in the SI. Additionaly, there is no detail about how the values in table are obtained, how many particles/spots were averaged etc.
2. Where does the Eq 3 come from? Citation and/or explanation is needed.
3. Why is Fig. 3 obtained only for 840 nm chosen? The same analysis should be shown for at least two other wavelenghts and samples and put into supplementary. How do you justify averaging all 5 samples into one spot, and not multiple measurements averaged for individual samples?
4. Xps- why only sample 5? The same analysis should be shown for other samples as well, and put into supplementary.
5. There are some minor errors in english , so I suggest going through the manusctript again.
After these concerns are addressed, the paper should be suitable for publishing.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
