Mass production of volume holographic optical elements (vHOEs) using Bayfol<sup>®</sup> HX photopolymer film in a roll-to-roll copy process

Bruder, Friedrich‐Karl; Fäcke, Thomas; Grote, Fabian; Hagen, Rainer; Hönel, Dennis; Koch, Eberhard; Rewitz, Christian; Walze, Günther; Wewer, Brita

doi:10.1117/12.2250933

Cited by 14 publications

(27 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, photopolymerizable materials show high diffraction efficiencies, allow real-time monitoring of the recording process, do not require development processes but only a bleaching process, can be produced from raw materials at low cost and give the possibility to modulate the properties through chemical synthesis [4]. Additional, photopolymers can be mass produced allowing to reducing production costs [30,31].…”

Section: Photopolymersmentioning

confidence: 99%

Volume Holographic Optical Elements as Solar Concentrators: An Overview

Ferrara

Striano²,

Coppola

2019

Applied Sciences

View full text Add to dashboard Cite

Generally, to reduce the area of a photovoltaic cell, which is typically very expensive, solar concentrators based on a set of mirrors or mechanical structures are used. However, such solar concentrators have some drawbacks, as they need a tracking system to track the sun’s position and also they suffer for the overheat due to the concentration of both light and heat on the solar cell. The fundamental advantages of volume holographic optical elements are very appealing for lightweight and cheap solar concentrators applications and can become a valuable asset that can be integrated into solar panels. In this paper, a review of volume holographic-based solar concentrators recorded on different holographic materials is presented. The physical principles and main advantages and disadvantages, such as their cool light concentration, selective wavelength concentrations and the possibility to implement passive solar tracking, are discussed. Different configurations and strategies are illustrated and the state-of-the-art is presented including commercially available systems.

show abstract

Section: Photopolymersmentioning

confidence: 99%

Volume Holographic Optical Elements as Solar Concentrators: An Overview

Ferrara

Striano²,

Coppola

2019

Applied Sciences

View full text Add to dashboard Cite

show abstract

“…Therefore at the end of this review we would like to touch on this aspect too. In [ 55 , 56 ] we reported about a contact copy process from a so-called master vHOE. In this copy process Bayfol ® HX film is laminated to this master vHOE.…”

Section: How To Mass Produce Volume Holographic Optical Elements Wmentioning

confidence: 99%

The Chemistry and Physics of Bayfol® HX Film Holographic Photopolymer

2017

Self Cite

View full text Add to dashboard Cite

Holographic photopolymers are a new technology to create passive diffractive optical elements by a pure laser interference recording. In this review, we explain the chemistry concepts of light harvesting in an interference pattern and the subsequent grating formation as chemical response. Using the example of the newly developed Bayfol ® HX film we discuss the reaction-diffusion driven photo-polymerization process for an index modulation formation to create volume phase gratings. Further we elucidate the selection of monomer chemistry and discuss details of the recording conditions based on the concept of exposure dosage and exposure time. Influences ranging from high dosage recording to low power recording are explained and how to affect the desired diffraction efficiency. Finally, we outline and demonstrate the process to mass manufacturing of volume phase gratings.

show abstract

“…Bayfol ® HX200 is an acrylate-based 2-chemistry photopolymer material; its composition and chemistry are described in detail in [26]. The chemical and physical properties of this material, such as the photo-initiation process, spectral photosensitivity, refractive index modulation, and bleaching, have been characterized [26][27][28]. The Bayfol ® HX200 film has an average refractive index of n o = 1.49 and a thickness of d = 16 µm, and it can provide a maximum refractive index modulation of ∆n = 0.03, per the manufacturer's specifications [29].…”

Section: Introductionmentioning

confidence: 99%

Thermal Properties of Bayfol® HX200 Photopolymer

2020

View full text Add to dashboard Cite

Bayfol® 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 125°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® HX200 material does not suffer from any permanent thermal degradation below 160°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 24°C to 100°C. Linear interpolation give a slope 4.5×10−4K−1 for unexposed film, with the extrapolated refractive index at 0°C equal to n0=1.51. This refractive index change decreases to 3×10−4K−1 when the material is fully cured with UV light, with a 0°C refractive index equal to n0=1.495. Spectral properties of a reflection hologram recorded at 532 nm was measured from 23°C to 171°C. A consistent 10 nm spectral shift increase was observed for the diffraction peak wavelength when the temperature reaches 171°C. From these spectral measurements, we calculated a coefficient of thermal expansion (CTE) of 384×10−6K−1 by using the coupled wave theory in order to determine the increase of the Bragg plane spacing with temperature.

show abstract

Mass production of volume holographic optical elements (vHOEs) using Bayfol^® HX photopolymer film in a roll-to-roll copy process

Cited by 14 publications

References 12 publications

Volume Holographic Optical Elements as Solar Concentrators: An Overview

Volume Holographic Optical Elements as Solar Concentrators: An Overview

The Chemistry and Physics of Bayfol® HX Film Holographic Photopolymer

Thermal Properties of Bayfol® HX200 Photopolymer

Contact Info

Product

Resources

About

Mass production of volume holographic optical elements (vHOEs) using Bayfol® HX photopolymer film in a roll-to-roll copy process

Cited by 14 publications

References 12 publications

Volume Holographic Optical Elements as Solar Concentrators: An Overview

Volume Holographic Optical Elements as Solar Concentrators: An Overview

The Chemistry and Physics of Bayfol® HX Film Holographic Photopolymer

Thermal Properties of Bayfol® HX200 Photopolymer

Contact Info

Product

Resources

About

Mass production of volume holographic optical elements (vHOEs) using Bayfol^® HX photopolymer film in a roll-to-roll copy process