Fabrication of a Composite Film Optic with High Transmittance in Vis and IR Regions for an Optical System

Round 1

Reviewer 1 Report

The manuscript describes the preparation and characterization of a lightweight composite polyimide film optic with an antireflective coating using an ion beam-assisted reactive sputtering method. The film exhibited high transmittance in the visible and infrared regions, with optical homogeneity and smooth surfaces. The thermal stability of the substrate polyimide film was maintained after the antireflective coating. The layer demonstrated hydrophobic properties as demonstrated by the analysis of the water absorption rate.

Overall, the study presents a promising approach for developing advanced optical materials with enhanced performance for application in large-diameter lightweight IR optical systems.  The findings of this study could be interesting to the readership of the journal.

Here is the list of some minor issues that should be revised:

Line 68: The heating procedure could be not clear. Please specify the initial and final temperatures.

Line 109: The formula for water absorption rate should be listed and numbered separately and then you should refer to the equation in the discussion. This would enhance readability.

Line 126: The PI film coated with designed antireflective film showed higher transmittance in visible, short (1.8~2.7 μm) and middle wavelength IR (3.3~5.4 μm) regions. The improvement in the average transmittance  (as compared to the bare PI film) is especially high in the short wavelength IR region (from 76 % to 86 %). In other wavelength regions, the improvement is more moderate. You should discuss the mechanism and possible reasons for this effect

Please go through the manuscript and repair typos, e.g. lack of space between values and units.

 

I recommend replacing “ * ” with “×”, e.g. lines 106, 109, Fig. 6.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Fabrication of Composite Film Optic with High Transmittance in Vis and IR Region for Optical System

 

In the present manuscript, the authors studied the composite polyimide film coated with antireflective materials which was deposited by ion beam reactive sputtering method. They found that the light composite polyimide exhibited high transmittance at visible (87%, in the wavelength range 0.5~0.8 μm), short (86%, 1.8~2.7), and middle (78%, 3.3~5.4 μm) wavelength infrared region. In addition, they found that a huge optical homogeneity (0.006 λ in RMS and 0.034 λ in PV, λ=632.8 nm) with smooth surfaces (RMS=0.786 nm).

 

The present manuscript looks like a technical report. What I would like the authors to do is explain physically the observation, like why the interference fringes in Fig. 3 are observed and their relation to the thickness and structure of the anti-reflection coating. These points are must be taken into consideration before the manuscript could be accepted for publication. After some major and carful revision of the following points:

v The authors used strange expressions repeated many times, like the expression ‘’polyimide film optic’’ What does this expression mean? Is it the optical properties of ’polyimide film?

 

v In Figure 3. the transmittance spectra of PI film before and after coating with antireflective film shows very nice interference peaks in the range 3-5.5μm, m. Can the authors explain physically the main reason behind the formation of these interference peaks?

 

 

v The authors show that the average surface roughness (nm) of PI film Fig.5(a)-(e) before and Fig.(f)-(j) after being coated with antireflective film is reduced; why?

 

v The English needs some careful revision, and I suggested some native English speakers and writers to look at the present manuscript, for example:

Figure 2(a) and Figure 2(b) shows the pictures of Ф50 mm film optic before and after coated with antireflective film by ion beam assisted reactive sputtering

 

This sentence Must be of the form

 

‘’Figures 2(a) and 2(b) show the pictures of Ф50 mm film optic before and after being coated with antireflective film by ion beam assisted reactive sputtering.’’

 

With my best regards

Fabrication of Composite Film Optic with High Transmittance in Vis and IR Region for Optical System

 

In the present manuscript, the authors studied the composite polyimide film coated with antireflective materials which was deposited by ion beam reactive sputtering method. They found that the light composite polyimide exhibited high transmittance at visible (87%, in the wavelength range 0.5~0.8 μm), short (86%, 1.8~2.7), and middle (78%, 3.3~5.4 μm) wavelength infrared region. In addition, they found that a huge optical homogeneity (0.006 λ in RMS and 0.034 λ in PV, λ=632.8 nm) with smooth surfaces (RMS=0.786 nm).

 

The present manuscript looks like a technical report. What I would like the authors to do is explain physically the observation, like why the interference fringes in Fig. 3 are observed and their relation to the thickness and structure of the anti-reflection coating. These points are must be taken into consideration before the manuscript could be accepted for publication. After some major and carful revision of the following points:

v The authors used strange expressions repeated many times, like the expression ‘’polyimide film optic’’ What does this expression mean? Is it the optical properties of ’polyimide film?

 

v In Figure 3. the transmittance spectra of PI film before and after coating with antireflective film shows very nice interference peaks in the range 3-5.5μm, m. Can the authors explain physically the main reason behind the formation of these interference peaks?

 

 

v The authors show that the average surface roughness (nm) of PI film Fig.5(a)-(e) before and Fig.(f)-(j) after being coated with antireflective film is reduced; why?

 

v The English needs some careful revision, and I suggested some native English speakers and writers to look at the present manuscript, for example:

Figure 2(a) and Figure 2(b) shows the pictures of Ф50 mm film optic before and after coated with antireflective film by ion beam assisted reactive sputtering

 

This sentence Must be of the form

 

‘’Figures 2(a) and 2(b) show the pictures of Ф50 mm film optic before and after being coated with antireflective film by ion beam assisted reactive sputtering.’’

 

With my best regards

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

the authors respond sufficiently to the raised questions and improve the manuscript for it to be accepted.