Bastos Ana, McKenna Barry, Lima Mário, André Paulo S, Carlos Luís D, Evans Rachel C, Ferreira Rute A S
Department of Physics, CICECO-Aveiro Institute of Materials and Department of Electronics, Telecommunications and Informatics, Instituto de Telecomunicações, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
School of Chemistry, Trinity College Dublin, Dublin 2, Ireland.
ACS Omega. 2018 Oct 22;3(10):13772-13781. doi: 10.1021/acsomega.8b01726. eCollection 2018 Oct 31.
Visible-light communications (VLCs) based on white light-emitting diodes (LEDs) are emerging as a low-cost and energy-efficient alternative solution to wireless communications. As white emitting LEDs use a combination of a long-lived yellow emission combined with the faster response of a blue emitting LED (∼460 nm), VLC technology requires amplification of the blue component to improve the signal-to-noise ratio. We report the fabrication and characterization of planar and channel waveguides based on a blue-emitting polyfluorene conjugated polyelectrolyte, namely, poly[9,9-bis(4-sulfonylbutoxyphenyl)fluorene-2,7-diyl--1,4-phenylene] (PBS-PFP) incorporated into diureasil organic-inorganic hybrids for optical amplification in VLC. Taking advantage of the diureasil host as a UV self-patternable material, direct UV laser writing was used to pattern channel waveguides with a larger refractive index (Δ=0.09) compared to the nonexposed region, enabling confinement and guidance of the PBS-PFP emission with a maximum optical gain efficiency value of 1.62 ± 0.02 cm μJ. This value is among the best figures of merit known for polymeric materials with additional advantages added by the diureasil hybrid host, namely, mechanical flexibility, thermal stability, and low insertion losses due to the nearly null refractive index contrast between the optical fiber and the amplification device, establishing the proposed approach as a promising cost-effective solution for optical amplification in VLCs.
基于白光发光二极管（LED）的可见光通信（VLC）正成为一种低成本、高能效的无线通信替代解决方案。由于白色发光LED采用了寿命长的黄色发射与蓝色发光LED（约460nm）更快响应的组合，VLC技术需要放大蓝色分量以提高信噪比。我们报告了基于蓝色发光聚芴共轭聚电解质，即聚[9,9-双（4-磺酰丁氧基苯基）芴-2,7-二亚基-1,4-亚苯基]（PBS-PFP）并入双脲硅有机-无机杂化材料中的平面和通道波导的制备及表征，用于VLC中的光放大。利用双脲硅主体作为紫外自图案化材料，采用直接紫外激光写入技术对通道波导进行图案化，其折射率（Δ=0.09）比未曝光区域大，能够限制和引导PBS-PFP发射，最大光增益效率值为1.62±0.02cm/μJ。该值是已知聚合物材料中最佳的品质因数之一，双脲硅杂化主体还具有额外优势，即机械柔韧性、热稳定性以及由于光纤与放大装置之间几乎为零的折射率对比度而导致的低插入损耗，从而使所提出的方法成为VLC中光放大的一种有前景的经济高效解决方案。
