Thermal Properties of Bayfol<sup>®</sup> HX200 Photopolymer

Bayfol<sup>®</sup> HX200 photopolymer is a holographic recording material used in a variety of applications such as a holographic combiner for a heads-up display and augmented reality, dispersive grating for spectrometers, and notch filters for Raman spectroscopy. For these systems, the...

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Main Authors: Pierre-Alexandre Blanche, Adoum H. Mahamat, Emmanuel Buoye
Format: Article
Language:English
Published: MDPI AG 2020-12-01
Series:Materials
Subjects:
Online Access:https://www.mdpi.com/1996-1944/13/23/5498
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author Pierre-Alexandre Blanche
Adoum H. Mahamat
Emmanuel Buoye
author_facet Pierre-Alexandre Blanche
Adoum H. Mahamat
Emmanuel Buoye
author_sort Pierre-Alexandre Blanche
collection DOAJ
description Bayfol<sup>®</sup> HX200 photopolymer is a holographic recording material used in a variety of applications such as a holographic combiner for a heads-up display and augmented reality, dispersive grating for spectrometers, and notch filters for Raman spectroscopy. For these systems, the thermal properties of the holographic material are extremely important to consider since temperature can affect the diffraction efficiency of the hologram as well as its spectral bandwidth and diffraction angle. These thermal variations are a consequence of the distance and geometry change of the diffraction Bragg planes recorded inside the material. Because temperatures can vary by a large margin in industrial applications (e.g., automotive industry standards require withstanding temperature up to <inline-formula><math display="inline"><semantics><mrow><mn>125</mn><msup><mspace width="3.33333pt"></mspace><mo>°</mo></msup></mrow></semantics></math></inline-formula>C), it is also essential to know at which temperature the material starts to be affected by permanent damage if the temperature is raised too high. Using thermogravimetric analysis, as well as spectral measurement on samples with and without hologram, we measured that the Bayfol<sup>®</sup> HX200 material does not suffer from any permanent thermal degradation below <inline-formula><math display="inline"><semantics><mrow><mn>160</mn><msup><mspace width="3.33333pt"></mspace><mo>°</mo></msup></mrow></semantics></math></inline-formula>C. From that point, a further increase in temperature induces a decrease in transmission throughout the entire visible region of the spectrum, leading to a reduced transmission for an original 82% down to 27% (including Fresnel reflection). We measured the refractive index change over the temperature range from <inline-formula><math display="inline"><semantics><mrow><mn>24</mn><msup><mspace width="3.33333pt"></mspace><mo>°</mo></msup></mrow></semantics></math></inline-formula>C to <inline-formula><math display="inline"><semantics><mrow><mn>100</mn><msup><mspace width="3.33333pt"></mspace><mo>°</mo></msup></mrow></semantics></math></inline-formula>C. Linear interpolation give a slope <inline-formula><math display="inline"><semantics><mrow><mn>4.5</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup><mspace width="3.33333pt"></mspace><msup><mi>K</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></semantics></math></inline-formula> for unexposed film, with the extrapolated refractive index at <inline-formula><math display="inline"><semantics><mrow><mn>0</mn><msup><mspace width="3.33333pt"></mspace><mo>°</mo></msup></mrow></semantics></math></inline-formula>C equal to <inline-formula><math display="inline"><semantics><mrow><msub><mi>n</mi><mn>0</mn></msub><mo>=</mo><mn>1.51</mn></mrow></semantics></math></inline-formula>. This refractive index change decreases to <inline-formula><math display="inline"><semantics><mrow><mn>3</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup><mspace width="3.33333pt"></mspace><msup><mi>K</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></semantics></math></inline-formula> when the material is fully cured with UV light, with a <inline-formula><math display="inline"><semantics><mrow><mn>0</mn><msup><mspace width="3.33333pt"></mspace><mo>°</mo></msup></mrow></semantics></math></inline-formula>C refractive index equal to <inline-formula><math display="inline"><semantics><mrow><msub><mi>n</mi><mn>0</mn></msub><mo>=</mo><mn>1.495</mn></mrow></semantics></math></inline-formula>. Spectral properties of a reflection hologram recorded at 532 nm was measured from <inline-formula><math display="inline"><semantics><mrow><mn>23</mn><msup><mspace width="3.33333pt"></mspace><mo>°</mo></msup></mrow></semantics></math></inline-formula>C to <inline-formula><math display="inline"><semantics><mrow><mn>171</mn><msup><mspace width="3.33333pt"></mspace><mo>°</mo></msup></mrow></semantics></math></inline-formula>C. A consistent 10 nm spectral shift increase was observed for the diffraction peak wavelength when the temperature reaches <inline-formula><math display="inline"><semantics><mrow><mn>171</mn><msup><mspace width="3.33333pt"></mspace><mo>°</mo></msup></mrow></semantics></math></inline-formula>C. From these spectral measurements, we calculated a coefficient of thermal expansion (CTE) of <inline-formula><math display="inline"><semantics><mrow><mn>384</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>6</mn></mrow></msup><mspace width="3.33333pt"></mspace><msup><mi>K</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></semantics></math></inline-formula> by using the coupled wave theory in order to determine the increase of the Bragg plane spacing with temperature.
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spelling doaj.art-11028fa3101e47589d87d2129f4189c42023-11-20T23:14:38ZengMDPI AGMaterials1996-19442020-12-011323549810.3390/ma13235498Thermal Properties of Bayfol<sup>®</sup> HX200 PhotopolymerPierre-Alexandre Blanche0Adoum H. Mahamat1Emmanuel Buoye2College of Optical Sciences, University of Arizona, 1630 E. University Blvd, Tucson, AZ 85721, USANaval Air Systems Command/NAWCAD, Patuxent River, MD 20670, USANaval Air Systems Command/NAWCAD, Patuxent River, MD 20670, USABayfol<sup>®</sup> HX200 photopolymer is a holographic recording material used in a variety of applications such as a holographic combiner for a heads-up display and augmented reality, dispersive grating for spectrometers, and notch filters for Raman spectroscopy. For these systems, the thermal properties of the holographic material are extremely important to consider since temperature can affect the diffraction efficiency of the hologram as well as its spectral bandwidth and diffraction angle. These thermal variations are a consequence of the distance and geometry change of the diffraction Bragg planes recorded inside the material. Because temperatures can vary by a large margin in industrial applications (e.g., automotive industry standards require withstanding temperature up to <inline-formula><math display="inline"><semantics><mrow><mn>125</mn><msup><mspace width="3.33333pt"></mspace><mo>°</mo></msup></mrow></semantics></math></inline-formula>C), it is also essential to know at which temperature the material starts to be affected by permanent damage if the temperature is raised too high. Using thermogravimetric analysis, as well as spectral measurement on samples with and without hologram, we measured that the Bayfol<sup>®</sup> HX200 material does not suffer from any permanent thermal degradation below <inline-formula><math display="inline"><semantics><mrow><mn>160</mn><msup><mspace width="3.33333pt"></mspace><mo>°</mo></msup></mrow></semantics></math></inline-formula>C. From that point, a further increase in temperature induces a decrease in transmission throughout the entire visible region of the spectrum, leading to a reduced transmission for an original 82% down to 27% (including Fresnel reflection). We measured the refractive index change over the temperature range from <inline-formula><math display="inline"><semantics><mrow><mn>24</mn><msup><mspace width="3.33333pt"></mspace><mo>°</mo></msup></mrow></semantics></math></inline-formula>C to <inline-formula><math display="inline"><semantics><mrow><mn>100</mn><msup><mspace width="3.33333pt"></mspace><mo>°</mo></msup></mrow></semantics></math></inline-formula>C. Linear interpolation give a slope <inline-formula><math display="inline"><semantics><mrow><mn>4.5</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup><mspace width="3.33333pt"></mspace><msup><mi>K</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></semantics></math></inline-formula> for unexposed film, with the extrapolated refractive index at <inline-formula><math display="inline"><semantics><mrow><mn>0</mn><msup><mspace width="3.33333pt"></mspace><mo>°</mo></msup></mrow></semantics></math></inline-formula>C equal to <inline-formula><math display="inline"><semantics><mrow><msub><mi>n</mi><mn>0</mn></msub><mo>=</mo><mn>1.51</mn></mrow></semantics></math></inline-formula>. This refractive index change decreases to <inline-formula><math display="inline"><semantics><mrow><mn>3</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup><mspace width="3.33333pt"></mspace><msup><mi>K</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></semantics></math></inline-formula> when the material is fully cured with UV light, with a <inline-formula><math display="inline"><semantics><mrow><mn>0</mn><msup><mspace width="3.33333pt"></mspace><mo>°</mo></msup></mrow></semantics></math></inline-formula>C refractive index equal to <inline-formula><math display="inline"><semantics><mrow><msub><mi>n</mi><mn>0</mn></msub><mo>=</mo><mn>1.495</mn></mrow></semantics></math></inline-formula>. Spectral properties of a reflection hologram recorded at 532 nm was measured from <inline-formula><math display="inline"><semantics><mrow><mn>23</mn><msup><mspace width="3.33333pt"></mspace><mo>°</mo></msup></mrow></semantics></math></inline-formula>C to <inline-formula><math display="inline"><semantics><mrow><mn>171</mn><msup><mspace width="3.33333pt"></mspace><mo>°</mo></msup></mrow></semantics></math></inline-formula>C. A consistent 10 nm spectral shift increase was observed for the diffraction peak wavelength when the temperature reaches <inline-formula><math display="inline"><semantics><mrow><mn>171</mn><msup><mspace width="3.33333pt"></mspace><mo>°</mo></msup></mrow></semantics></math></inline-formula>C. From these spectral measurements, we calculated a coefficient of thermal expansion (CTE) of <inline-formula><math display="inline"><semantics><mrow><mn>384</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>6</mn></mrow></msup><mspace width="3.33333pt"></mspace><msup><mi>K</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></semantics></math></inline-formula> by using the coupled wave theory in order to determine the increase of the Bragg plane spacing with temperature.https://www.mdpi.com/1996-1944/13/23/5498photopolymertemperaturehologramCTEthermal degradationrefractive index
spellingShingle Pierre-Alexandre Blanche
Adoum H. Mahamat
Emmanuel Buoye
Thermal Properties of Bayfol<sup>®</sup> HX200 Photopolymer
Materials
photopolymer
temperature
hologram
CTE
thermal degradation
refractive index
title Thermal Properties of Bayfol<sup>®</sup> HX200 Photopolymer
title_full Thermal Properties of Bayfol<sup>®</sup> HX200 Photopolymer
title_fullStr Thermal Properties of Bayfol<sup>®</sup> HX200 Photopolymer
title_full_unstemmed Thermal Properties of Bayfol<sup>®</sup> HX200 Photopolymer
title_short Thermal Properties of Bayfol<sup>®</sup> HX200 Photopolymer
title_sort thermal properties of bayfol sup r sup hx200 photopolymer
topic photopolymer
temperature
hologram
CTE
thermal degradation
refractive index
url https://www.mdpi.com/1996-1944/13/23/5498
work_keys_str_mv AT pierrealexandreblanche thermalpropertiesofbayfolsupsuphx200photopolymer
AT adoumhmahamat thermalpropertiesofbayfolsupsuphx200photopolymer
AT emmanuelbuoye thermalpropertiesofbayfolsupsuphx200photopolymer