Everardo Vargas-Rodríguez, A. Guzmán-Chávez, Raja Zaman
{"title":"Determination of the nonlinear thermal expansion coefficient of an epoxy used as expander and its effects over a Fabry-Perot cavity filled with a polymer.","authors":"Everardo Vargas-Rodríguez, A. Guzmán-Chávez, Raja Zaman","doi":"10.1364/ome.533001","DOIUrl":"https://doi.org/10.1364/ome.533001","url":null,"abstract":"","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141686627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuang Cheng, Yang Chen, Bingchen Lv, Zhiming Shi, Yuanyuan Yue, Yuping Jia, Ke Jiang, Xiaoyu Wei, Dabing Li, Shanli Zhang, Xiaojuan Sun
The present study proposes a two-step doping strategy for achieving efficient Mg doping of h-BN, involving an additional post-annealing treatment. This approach leads to ∼108-fold enhancement in conductivity of h-BN, compared with the as-doped h-BN grown by low-pressure chemical vapor deposition. The mechanism for large enhancement in h-BN doping efficiency after post-annealing was investigated, providing evidence that this treatment not only facilitates the nanoparticle decomposition and incorporation of Mg atoms into h-BN, but also restores its lattice defects. The efficient two-step doping strategy for p-type h-BN in this study enlightens its promising prospects for ultraviolet optoelectronic devices.
{"title":"Enhanced p-type conductivity of hexagonal boron nitride by an efficient two-step doping strategy","authors":"Yuang Cheng, Yang Chen, Bingchen Lv, Zhiming Shi, Yuanyuan Yue, Yuping Jia, Ke Jiang, Xiaoyu Wei, Dabing Li, Shanli Zhang, Xiaojuan Sun","doi":"10.1364/ome.523859","DOIUrl":"https://doi.org/10.1364/ome.523859","url":null,"abstract":"The present study proposes a two-step doping strategy for achieving efficient Mg doping of h-BN, involving an additional post-annealing treatment. This approach leads to ∼10<jats:sup>8</jats:sup>-fold enhancement in conductivity of h-BN, compared with the as-doped h-BN grown by low-pressure chemical vapor deposition. The mechanism for large enhancement in h-BN doping efficiency after post-annealing was investigated, providing evidence that this treatment not only facilitates the nanoparticle decomposition and incorporation of Mg atoms into h-BN, but also restores its lattice defects. The efficient two-step doping strategy for p-type h-BN in this study enlightens its promising prospects for ultraviolet optoelectronic devices.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141863672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pan Liang, Xin Jia, Hua Zhao, Rongrong Hu, Kai Jiang
YAG:Ce3+ nanocrystals are promising bio-labeling materials due to their low toxicity and high photostability. It is in demand to efficiently synthesize YAG:Ce3+ nanocrystals of a small size. Pulse laser ablation is an approach to produce nanoparticles directly from bulk materials with the advantages of smaller particle sizes and lower production costs. Here, we present the synthesis of YAG:Ce3+ nanocrystals from bulk crystal using the femtosecond laser ablation method in liquid. Comparing the liquid environment, we demonstrated that the lauryl dimethylaminoacetic acid betain (LDA) aqueous solution is preferred for the formation of smaller-sized YAG:Ce3+ nanoparticles than deionized water due to the attractiveness between the LDA molecules and the YAG:Ce3+ nanoparticles. We also verified that the high laser repetition rate had no effect on the average size of YAG:Ce3+ nanocrystals, where the fragmentation process is saturated under a high laser repetition rate. This study provides a simple and effective method to synthesize small size YAG:Ce3+ nanoparticles by femtosecond laser ablation in liquid.
{"title":"Femtosecond laser synthesis of YAG:Ce3+ nanoparticles in liquid","authors":"Pan Liang, Xin Jia, Hua Zhao, Rongrong Hu, Kai Jiang","doi":"10.1364/ome.530234","DOIUrl":"https://doi.org/10.1364/ome.530234","url":null,"abstract":"YAG:Ce<jats:sup>3+</jats:sup> nanocrystals are promising bio-labeling materials due to their low toxicity and high photostability. It is in demand to efficiently synthesize YAG:Ce<jats:sup>3+</jats:sup> nanocrystals of a small size. Pulse laser ablation is an approach to produce nanoparticles directly from bulk materials with the advantages of smaller particle sizes and lower production costs. Here, we present the synthesis of YAG:Ce<jats:sup>3+</jats:sup> nanocrystals from bulk crystal using the femtosecond laser ablation method in liquid. Comparing the liquid environment, we demonstrated that the lauryl dimethylaminoacetic acid betain (LDA) aqueous solution is preferred for the formation of smaller-sized YAG:Ce<jats:sup>3+</jats:sup> nanoparticles than deionized water due to the attractiveness between the LDA molecules and the YAG:Ce<jats:sup>3+</jats:sup> nanoparticles. We also verified that the high laser repetition rate had no effect on the average size of YAG:Ce<jats:sup>3+</jats:sup> nanocrystals, where the fragmentation process is saturated under a high laser repetition rate. This study provides a simple and effective method to synthesize small size YAG:Ce<jats:sup>3+</jats:sup> nanoparticles by femtosecond laser ablation in liquid.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141863674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We proposed a nanohole-based silicon (Si) absorber structure to enhance the light absorption of thin-film Si solar cells. Our proposed structures exhibited excellent performances harnessing the light-matter interaction phenomenon with a few microns of thick Si (3 µm). We employed the finite-difference time-domain method to analyze the optical properties and solved Poisson’s, continuity, and heat transfer equations to analyze the electrical and thermal properties of our proposed structures, operating in the wavelength range from 300 to 1100 nm. We obtained a maximum average absorption of 72.6% for our proposed square hole Si absorber structure. The power conversion efficiency and short circuit current density were calculated to be 20.74% and 39.91 mA/cm2. We achieved polarization-insensitive performance due to the symmetrical nature of the structure. The temperature of our proposed structure was increased by ∼10 K due to light absorption for different ambient temperatures. Moreover, we found our proposed structure was thermally stable over time. Our proposed structures can enhance the absorption of Si nanostructures, which can be conducive to designing Si-thin solar cells for energy harvesting.
{"title":"Silicon nanohole based enhanced light absorbers for thin film solar cell applications","authors":"Rony Das, Badhan Golder, Dip Sarker, Arif Ahammad","doi":"10.1364/ome.528499","DOIUrl":"https://doi.org/10.1364/ome.528499","url":null,"abstract":"We proposed a nanohole-based silicon (Si) absorber structure to enhance the light absorption of thin-film Si solar cells. Our proposed structures exhibited excellent performances harnessing the light-matter interaction phenomenon with a few microns of thick Si (3 <jats:italic>µ</jats:italic>m). We employed the finite-difference time-domain method to analyze the optical properties and solved Poisson’s, continuity, and heat transfer equations to analyze the electrical and thermal properties of our proposed structures, operating in the wavelength range from 300 to 1100 nm. We obtained a maximum average absorption of 72.6% for our proposed square hole Si absorber structure. The power conversion efficiency and short circuit current density were calculated to be 20.74% and 39.91 mA/cm<jats:sup>2</jats:sup>. We achieved polarization-insensitive performance due to the symmetrical nature of the structure. The temperature of our proposed structure was increased by ∼10 K due to light absorption for different ambient temperatures. Moreover, we found our proposed structure was thermally stable over time. Our proposed structures can enhance the absorption of Si nanostructures, which can be conducive to designing Si-thin solar cells for energy harvesting.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141872879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
High-intensity X-ray free electron laser (XFEL) beams require optics made of materials with minimal radiation absorption, high diffraction efficiency, and high radiation hardness. Multilayer Laue lenses (MLLs) are diffraction-based X-ray optics that can focus XFEL beams, as already demonstrated with tungsten carbide/silicon carbide (WC/SiC)-based MLLs. However, high atomic number materials such as tungsten strongly absorb X-rays, resulting in high heat loads. Numerical simulations predict much lower heat loads in MLLs consisting of low atomic number Z materials, although such MLLs have narrower rocking curve widths. In this paper, we first screen various multilayer candidates and then focus on Mo2C/SiC multilayer due to its high diffraction efficiency. According to numerical simulations, the maximum temperature in this multilayer should remain below 300°C if the MLL made out of this multilayer is exposed to an XFEL beam of 17.5 keV photon energy, 1 mJ energy per pulse and 10 kHz pulse repetition rate. To understand the thermal stability of the Mo2C/SiC multilayer, we performed a study on the multilayers of three different periods (1.5, 5, and 12 nm) and different Mo2C to SiC ratios. We monitored their periods, crystallinity, and stress as a function of annealing temperature for two different heating rates. The results presented in this paper indicate that Mo2C/SiC-based MLLs are viable for focusing XFEL beams without being damaged under these conditions.
高强度 X 射线自由电子激光器（XFEL）光束需要由辐射吸收最小、衍射效率高和辐射硬度高的材料制成的光学器件。多层劳厄透镜（MLL）是一种基于衍射的 X 射线光学器件，可以聚焦 XFEL 光束，基于碳化钨/碳化硅（WC/SiC）的多层劳厄透镜已经证明了这一点。然而，钨等高原子序数材料会强烈吸收 X 射线，从而导致高热负荷。数值模拟预测，由低原子序数 Z 材料组成的 MLL 的热负荷要低得多，尽管这种 MLL 的摇摆曲线宽度较窄。在本文中，我们首先筛选了各种候选多层材料，然后重点研究了具有高衍射效率的 Mo2C/SiC 多层材料。根据数值模拟，如果将该多层膜制成的 MLL 暴露在光子能量为 17.5 keV、每脉冲能量为 1 mJ、脉冲重复率为 10 kHz 的 XFEL 光束中，该多层膜的最高温度应保持在 300°C 以下。为了了解 Mo2C/SiC 多层的热稳定性，我们对三种不同周期（1.5、5 和 12 nm）和不同 Mo2C 与 SiC 比率的多层进行了研究。在两种不同的加热速率下，我们监测了它们的周期、结晶度和应力与退火温度的函数关系。本文介绍的结果表明，基于 Mo2C/SiC 的 MLL 可用于聚焦 XFEL 光束，而不会在这些条件下受到损坏。
{"title":"On the thermal stability of multilayer optics for use with high X-ray intensities","authors":"Margarita Zakharova, Zlatko Rek, Božidar Šarler, Saša Bajt","doi":"10.1364/ome.527226","DOIUrl":"https://doi.org/10.1364/ome.527226","url":null,"abstract":"High-intensity X-ray free electron laser (XFEL) beams require optics made of materials with minimal radiation absorption, high diffraction efficiency, and high radiation hardness. Multilayer Laue lenses (MLLs) are diffraction-based X-ray optics that can focus XFEL beams, as already demonstrated with tungsten carbide/silicon carbide (WC/SiC)-based MLLs. However, high atomic number materials such as tungsten strongly absorb X-rays, resulting in high heat loads. Numerical simulations predict much lower heat loads in MLLs consisting of low atomic number Z materials, although such MLLs have narrower rocking curve widths. In this paper, we first screen various multilayer candidates and then focus on Mo<jats:sub>2</jats:sub>C/SiC multilayer due to its high diffraction efficiency. According to numerical simulations, the maximum temperature in this multilayer should remain below 300°C if the MLL made out of this multilayer is exposed to an XFEL beam of 17.5 keV photon energy, 1 mJ energy per pulse and 10 kHz pulse repetition rate. To understand the thermal stability of the Mo<jats:sub>2</jats:sub>C/SiC multilayer, we performed a study on the multilayers of three different periods (1.5, 5, and 12 nm) and different Mo<jats:sub>2</jats:sub>C to SiC ratios. We monitored their periods, crystallinity, and stress as a function of annealing temperature for two different heating rates. The results presented in this paper indicate that Mo<jats:sub>2</jats:sub>C/SiC-based MLLs are viable for focusing XFEL beams without being damaged under these conditions.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141863673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Umit Demirbas, Christian Rentschler, Zhelin Zhang, Mikhail Pergament, Nicholas H. Matlis, Franz X. Kärtner
In this study, we demonstrate the capabilities of the pulse train excitation approach in determining key material properties of nonlinear crystals, such as refractive index, thermo-optic coefficient, and absorption. The method provides reliable results even at relatively low THz frequencies, where other characterization methods, such as THz time-domain spectroscopy, have difficulties. To illustrate the capabilities of our approach, we used pulse trains with 800-fs long pulses and adjustable time delay to investigate the material properties of periodically poled lithium niobate (PPLN) crystal with a poling period of 400 µm. Via scanning the incident pulse-train frequency, we measured the frequency response of the crystal at different temperatures (78-350 K), which enabled us to determine the temperature dependence of the refractive index and thermo-optic coefficient of the PPLN crystal around 275 GHz with very high precision. We further studied the variation of THz generation efficiency with temperature in detail to understand the temperature dependence of THz absorption in PPLN material. The technique employed is quite general and could be applied to both other frequency ranges and nonlinear crystals.
{"title":"Temperature dependence of THz generation efficiency, THz refractive index, and THz absorption in lithium-niobate around 275 GHz","authors":"Umit Demirbas, Christian Rentschler, Zhelin Zhang, Mikhail Pergament, Nicholas H. Matlis, Franz X. Kärtner","doi":"10.1364/ome.528491","DOIUrl":"https://doi.org/10.1364/ome.528491","url":null,"abstract":"In this study, we demonstrate the capabilities of the pulse train excitation approach in determining key material properties of nonlinear crystals, such as refractive index, thermo-optic coefficient, and absorption. The method provides reliable results even at relatively low THz frequencies, where other characterization methods, such as THz time-domain spectroscopy, have difficulties. To illustrate the capabilities of our approach, we used pulse trains with 800-fs long pulses and adjustable time delay to investigate the material properties of periodically poled lithium niobate (PPLN) crystal with a poling period of 400 µm. Via scanning the incident pulse-train frequency, we measured the frequency response of the crystal at different temperatures (78-350 K), which enabled us to determine the temperature dependence of the refractive index and thermo-optic coefficient of the PPLN crystal around 275 GHz with very high precision. We further studied the variation of THz generation efficiency with temperature in detail to understand the temperature dependence of THz absorption in PPLN material. The technique employed is quite general and could be applied to both other frequency ranges and nonlinear crystals.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141872881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Frederik van Schoonhoven, Yoshitaka Tomishige, Adrian Abazi, Alejandro Sánchez-Postigo, Jinghan Chen, Yuya Mikami, Naoya Tate, Yuji Oki, Carsten Schuck, Hiroaki Yoshioka
We incorporate a passive wedge-shaped organic microdisk supporting spatially separated whispering gallery modes into an SU-8 photonic integrated circuit (PIC) by using direct inkjet printing. This innovative method allows the mixing of multiple organic materials, enabling tunability of the refractive index of microdisks, thereby overcoming limitations of single-material resonators from conventional lithography. In this study, the microdisk resonator, with a refractive index matching that of SU-8 by mixing hyperbranched polymers, is mounted horizontally to an optical waveguide, achieving directional coupling between the microdisk and PIC at a wavelength of 1550 nm. Geometrical conditions for successful coupling were obtained by measuring the cross-sectional profile of the fabricated structure’s surface via atomic force microscopy, determining ways to adjust the coupling efficiency.
{"title":"Inkjet-printed waveguide-coupled passive wedge-shaped microdisk resonator with refractive index tunability","authors":"Frederik van Schoonhoven, Yoshitaka Tomishige, Adrian Abazi, Alejandro Sánchez-Postigo, Jinghan Chen, Yuya Mikami, Naoya Tate, Yuji Oki, Carsten Schuck, Hiroaki Yoshioka","doi":"10.1364/ome.528582","DOIUrl":"https://doi.org/10.1364/ome.528582","url":null,"abstract":"We incorporate a passive wedge-shaped organic microdisk supporting spatially separated whispering gallery modes into an SU-8 photonic integrated circuit (PIC) by using direct inkjet printing. This innovative method allows the mixing of multiple organic materials, enabling tunability of the refractive index of microdisks, thereby overcoming limitations of single-material resonators from conventional lithography. In this study, the microdisk resonator, with a refractive index matching that of SU-8 by mixing hyperbranched polymers, is mounted horizontally to an optical waveguide, achieving directional coupling between the microdisk and PIC at a wavelength of 1550 nm. Geometrical conditions for successful coupling were obtained by measuring the cross-sectional profile of the fabricated structure’s surface via atomic force microscopy, determining ways to adjust the coupling efficiency.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141863759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We designed slow-light waveguides with a wide mode area based on slab-type valley photonic crystal (VPhC) heterostructures which are composed of a graphene-like PhC sandwiched by two topologically distinct VPhCs. The group velocity of the topological guided mode hosted in a VPhC heterostructure can be slowed down by shifting the VPhC lattice toward the graphene-like PhC at the domain interfaces. Simultaneously, the mode width of the slow-light topological guided mode can be widened by increasing the size of the graphene-like PhC domain. We found that employing the graphene-like structure at the center domain is crucial for realizing a topological single-guided mode in such heterostructures. Furthermore, the impact of random fluctuations in air-hole size in the graphene-like domain was numerically investigated. Our simulation results demonstrate that the transmittance for the slow-light states can be kept high as far as the size fluctuation is small although it drops faster than that for fast-light states when the disorder level increases. The designed wide-mode-area slow-light waveguides are based on hole-based PhCs, offering novel on-chip applications of topological waveguides.
{"title":"Wide-mode-area slow light waveguides in valley photonic crystal heterostructures","authors":"Chengkun Zhang, Yasutomo Ota, Satoshi Iwamoto","doi":"10.1364/ome.525349","DOIUrl":"https://doi.org/10.1364/ome.525349","url":null,"abstract":"We designed slow-light waveguides with a wide mode area based on slab-type valley photonic crystal (VPhC) heterostructures which are composed of a graphene-like PhC sandwiched by two topologically distinct VPhCs. The group velocity of the topological guided mode hosted in a VPhC heterostructure can be slowed down by shifting the VPhC lattice toward the graphene-like PhC at the domain interfaces. Simultaneously, the mode width of the slow-light topological guided mode can be widened by increasing the size of the graphene-like PhC domain. We found that employing the graphene-like structure at the center domain is crucial for realizing a topological single-guided mode in such heterostructures. Furthermore, the impact of random fluctuations in air-hole size in the graphene-like domain was numerically investigated. Our simulation results demonstrate that the transmittance for the slow-light states can be kept high as far as the size fluctuation is small although it drops faster than that for fast-light states when the disorder level increases. The designed wide-mode-area slow-light waveguides are based on hole-based PhCs, offering novel on-chip applications of topological waveguides.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141872880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study demonstrates a fabrication method of a porous brightness enhancement film (pBEF) that offers brightness enhancement, light diffusion, color shift reduction, and improved thermal stability. During the ultraviolet imprinting and solvent evaporation processes, the nano/submicron-sized air pores are generated within the polymer prism structure, and micropatterns spontaneously form on the prism surface. The inner pores ranging from 30 to 450 nm can effectively scatter light to mitigate color shift, which is caused by multiple internal reflections within the prism structure. The micropatterns have multiple rings formed one around another with 5–15-µm diameter on the prism surface improve visual quality. Moreover, the obtained functions are achieved in a single film solution, obviating the need for using multiple materials, and the fabrication process is relatively simple and fast as it is conducted under ambient conditions. When the pBEF is integrated into a liquid-crystal display backlight, it provides the brightness enhancement performance and comparable viewing angle distribution of a regular BEF combined with an additional diffuser (two films) and increases brightness by ∼8% compared to a bead prism (particle-based BEF). Additionally, it reduces the redshift (Δxy) from 0.1605 to 0.1415. Furthermore, the pBEF exhibits a lower coefficient of thermal expansion than the regular BEF.
{"title":"Design and fabrication of a porous prism film for display backlight applications","authors":"Fang-Hsuan Su, Ray-Hua Horng, Dong-Sing Wuu","doi":"10.1364/ome.528148","DOIUrl":"https://doi.org/10.1364/ome.528148","url":null,"abstract":"This study demonstrates a fabrication method of a porous brightness enhancement film (pBEF) that offers brightness enhancement, light diffusion, color shift reduction, and improved thermal stability. During the ultraviolet imprinting and solvent evaporation processes, the nano/submicron-sized air pores are generated within the polymer prism structure, and micropatterns spontaneously form on the prism surface. The inner pores ranging from 30 to 450 nm can effectively scatter light to mitigate color shift, which is caused by multiple internal reflections within the prism structure. The micropatterns have multiple rings formed one around another with 5–15-µm diameter on the prism surface improve visual quality. Moreover, the obtained functions are achieved in a single film solution, obviating the need for using multiple materials, and the fabrication process is relatively simple and fast as it is conducted under ambient conditions. When the pBEF is integrated into a liquid-crystal display backlight, it provides the brightness enhancement performance and comparable viewing angle distribution of a regular BEF combined with an additional diffuser (two films) and increases brightness by ∼8% compared to a bead prism (particle-based BEF). Additionally, it reduces the redshift (Δ<jats:italic toggle=\"yes\">xy</jats:italic>) from 0.1605 to 0.1415. Furthermore, the pBEF exhibits a lower coefficient of thermal expansion than the regular BEF.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141863760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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