Hyperbranched-polymer nanocomposite gratings with ultrahigh refractive index modulation amplitudes for volume holographic optical elements

2019 ◽  
Author(s):  
Yasuo Tomita ◽  
Toshi Aoi ◽  
Juro Oshima ◽  
Keisuke Odoi
Keyword(s):  
Refractive Index ◽  
Hyperbranched Polymer ◽  
Polymer Nanocomposite ◽  
Refractive Index Modulation ◽  
Optical Elements ◽  
Holographic Optical Elements ◽  
Index Modulation

scholarly journals Ag nanoparticle-enhanced alkyl radical generation in photopolymerization for holographic recording

Nanophotonics ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1795-1802 ◽  
Author(s):  
Jinxin Guo ◽  
Jialing Jian ◽  
Meng Wang ◽  
Yasuo Tomita ◽  
Lin Cao ◽  
...  
Keyword(s):  
Refractive Index ◽  
Ag Nanoparticles ◽  
Polymer Nanocomposite ◽  
Dark Field ◽  
Holographic Recording ◽  
Refractive Index Modulation ◽  
Modulation Amplitude ◽  
Ag Nanoparticle ◽  
Paramagnetic Resonance ◽  
Index Modulation

AbstractWe report a new Ag nanoparticle-dispersed polymer nanocomposite for volume holographic recording through acrylic photopolymerization. The initial grating buildup dynamics at the inhibition stage are measured at various Ag nanoparticle concentrations. The refractive index modulation amplitude as large as 0.0069 at 633 nm is seen at the optimum Ag nanoparticle concentration of 1 wt.% with respect to the monomer. Electron paramagnetic resonance measurements show that Ag nanoparticles influence both the generation of alkyl radicals and the scavenging of oxygen in free radical photopolymerization. This mechanism intrinsically determines the molecular weight of polymer being formed and, thereby, affects the refractive index modulation amplitude of the formed grating as a function of Ag nanoparticle concentrations. Moreover, we confirm that two-beam holographic exposure leads to a periodic assembly of dispersed Ag nanoparticles using a dark-field microscopy. Our results suggest a simple way to control the photopolymerization and, therefore, to tailor polymers for practical uses.

scholarly journals Study of the Effect of Methyldiethanolamine Initiator on the Recording Properties of Acrylamide Based Photopolymer

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 734
Author(s):  
Brian Rogers ◽  
Suzanne Martin ◽  
Izabela Naydenova
Keyword(s):  
Refractive Index ◽  
Diffraction Efficiency ◽  
Prolonged Exposure ◽  
Uv Light ◽  
Holographic Recording ◽  
Refractive Index Modulation ◽  
Optical Elements ◽  
The Stability ◽  
Angular Selectivity ◽  
Index Modulation

The use of Holographic Optical Elements (HOEs) in applications, such as in light shaping and redirection, requires certain characteristics such as a high Diffraction Efficiency, low angular selectivity and stability against UV damage. In order to maximize the performance of the HOEs, photosensitive materials are needed that have been optimised for the characteristics that are of particular importance in that application. At the core of the performance of these devices is the refractive index modulation created during holographic recording. Typically, a higher refractive index modulation will enable greater light Diffraction Efficiency and also operation with thinner devices, which in turn decreases the angular selectivity and the stability of the refractive index modulation introduced during recording, which is key to the longevity of the device. Solar concentrators based on volume HOEs can particularly benefit from thinner devices, because, for a solar concentrator to have a high angular working range, thinner photopolymer layers with a smaller angular selectivity are required. This paper presents an optimisation of an acrylamide-based photopolymer formulation for an improved refractive index modulation and recording speed. This was achieved by studying the effect of the concentration of acrylamide and the influence of different initiators in the photopolymer composition on the diffraction efficiency of holographic gratings. Two initiators of different molecular weights were compared: triethanolamine (TEA) and methyldiethanolamine (MDEA). A fivefold increase in the rate of grating formation was achieved through the modification of the acrylamide concentration alone, and it was also found that holograms recorded with MDEA as the initiator performed the best and recorded up to 25% faster than a TEA-based photopolymer. Finally, tests were carried out on the stability of the protected and unprotected photopolymer layers when subjected to UV light. The properties exhibited by this photopolymer composition make it a promising material for the production of optical elements and suitable for use in applications requiring prolonged exposure to UV light when protected by a thin melinex cover.

Optical properties of a photopolymer with large refractive index modulation for holographic application

2004 ◽  
Author(s):  
Chang-Won Shin ◽  
Nam Kim ◽  
Won-Sun Kim ◽  
Yong-Cheol Jeong ◽  
Jung-Ki Park
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Refractive Index Modulation ◽  
Index Modulation

scholarly journals Wavelength selective refractive index modulation in a ROMP derived polymer bearing phenyl- and ortho-nitrobenzyl ester groups

2013 ◽  
Vol 1 (25) ◽  
pp. 3931 ◽  
Author(s):  
Matthias Edler ◽  
Stefan Mayrbrugger ◽  
Alexander Fian ◽  
Gregor Trimmel ◽  
Simone Radl ◽  
...  
Keyword(s):  
Refractive Index ◽  
Refractive Index Modulation ◽  
Polymer Bearing ◽  
Index Modulation

Refractive-Index Modulation by Means of Photosensitive Liquid Crystals

2002 ◽  
Vol 375 ◽  
pp. 45-60 ◽  
Author(s):  
Tomiki Ikeda ◽  
Satoshi Yoneyama ◽  
Takahiro Yamamoto ◽  
Makoto Hasegawa
Keyword(s):  
Refractive Index ◽  
Liquid Crystals ◽  
Refractive Index Modulation ◽  
Index Modulation

A Humidity Sensor Based on Ultra-Long-Period Fiber Gratings with Asymmetric Refractive Index Modulation

2009 ◽  
Vol 36 (8) ◽  
pp. 2042-2045 ◽  
Author(s):  
宋韵 Song Yun ◽  
朱涛 Zhu Tao ◽  
饶云江 Rao Yunjiang ◽  
赵英伟 Zhao Yingwei
Keyword(s):  
Refractive Index ◽  
Humidity Sensor ◽  
Refractive Index Modulation ◽  
Fiber Gratings ◽  
Long Period ◽  
Long Period Fiber Gratings ◽  
Index Modulation
Sign in / Sign up

Export Citation Format

Share Document