Kumi Barimah Eric, Rahayu Sri, Ziarko Marcin W, Bamiedakis Nikolaos, White Ian H, Penty Richard V, Kale Girish M, Jose Gin
School of Chemical and Process Engineering, University of Leeds, Clarendon Road, Leeds LS2 9JT, U.K.
Centre for Photonic Systems, Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, U.K.
ACS Omega. 2020 Apr 14;5(16):9224-9232. doi: 10.1021/acsomega.0c00040. eCollection 2020 Apr 28.
Erbium-doped nanocrystal (NC)-dispersed polymer thin films are attractive core materials for use in optical waveguides as they can provide high optical gain and enable the formation of compact waveguide amplifiers. Nonetheless, there are significant challenges associated with obtaining good dispersibility of NCs into a polymer matrix and favorable optical properties. Therefore, in this paper, we report the fabrication of Er-doped ceria (EGC) NCs employing the Leeds alginate process (LAP) and their incorporation into a siloxane polymer matrix. The surface morphology and compositional, structural, and optical properties of the fabricated films are evaluated to assess the NC dispersion and their suitability for the waveguide amplifier. The photoluminescence (PL) and lifetime measurements of the NCs-polymer nanocomposite thin film samples show intense, broadband PL emission of the Er ions at 1534 nm (I → I transition) with a full width at half-maximum (fwhm) of ∼64 nm and lifetime in the range of 2.6-3.0 ms. The inhomogeneously broadened PL spectra and improvement in lifetime of NCs in the polymer are important results that we report. The EGC NCs-polymer nanocomposite thin films also exhibit excellent transparency in the NIR wavelength range and a refractive index in the range of 1.53-1.58 in the visible wavelength. The work presented here clearly demonstrates the potential of using high-quality Er-doped nanocomposite polymer thin films for interesting applications such as compact low-cost waveguide amplifiers and lasers.
掺铒纳米晶体（NC）分散的聚合物薄膜是用于光波导的有吸引力的核心材料，因为它们可以提供高光学增益并能够形成紧凑的波导放大器。尽管如此，在使纳米晶体在聚合物基体中获得良好的分散性以及良好的光学性能方面仍存在重大挑战。因此，在本文中，我们报告了采用利兹藻酸盐工艺（LAP）制备掺铒二氧化铈（EGC）纳米晶体及其掺入硅氧烷聚合物基体的情况。对制备的薄膜的表面形貌、组成、结构和光学性能进行评估，以评估纳米晶体的分散情况及其对波导放大器的适用性。纳米晶体 - 聚合物纳米复合薄膜样品的光致发光（PL）和寿命测量结果表明，铒离子在1534 nm处（I→I跃迁）有强烈的宽带PL发射，半高宽（fwhm）约为64 nm，寿命在2.6 - 3.0 ms范围内。我们报道的聚合物中纳米晶体的非均匀加宽PL光谱和寿命的改善是重要结果。EGC纳米晶体 - 聚合物纳米复合薄膜在近红外波长范围内也表现出优异的透明度，在可见光波长范围内折射率在1.53 - 1.58范围内。本文所展示的工作清楚地证明了使用高质量掺铒纳米复合聚合物薄膜用于诸如紧凑低成本波导放大器和激光器等有趣应用的潜力。
