Sznitko Lech, Romano Luigi, Wawrzynczyk Dominika, Cyprych Konrad, Mysliwiec Jaroslaw, Pisignano Dario
Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland.
Dipartimento di Matematica e Fisica "Ennio De Giorgi", Università Del Salento, Via Arnesano I-73100, Lecce, Italy.
RSC Adv. 2018 Jul 3;8(43):24175-24181. doi: 10.1039/c8ra03640c.
We present stacked organic lasing heterostructures made by different species of light-emitting electrospun fibers, each able to provide optical gain in a specific spectral region. A hierarchical architecture is obtained by conformable layers of fibers with disordered two-dimensional organization and three-dimensional compositional heterogeneity. Lasing polymer fibers are superimposed in layers, showing asymmetric optical behavior from the two sides of the organic heterostructure, and tailored and bichromatic stimulated emission depending on the excitation direction. A marginal role of energy acceptor molecules in determining quenching of high-energy donor species is evidenced by luminescence decay time measurements. These findings show that non-woven stacks of light-emitting electrospun fibers doped with different dyes exhibit critically-suppressed Förster resonance energy transfer, limited at joints between different fiber species. This leads to the obtaining of hybrid materials with mostly physically-separated acceptors and donors, thus largely preventing donor quenching and making it much easier to achieve simultaneous lasing from multiple spectral bands. Coherent backscattering experiments are also performed on the system, suggesting the onset of random lasing features. These new organic lasing systems might find application in microfluidic devices where flexible and bidirectional excitation sources are needed, optical sensors, and nanophotonics.
我们展示了由不同种类的发光电纺纤维制成的堆叠式有机激光异质结构，每种纤维都能够在特定光谱区域提供光学增益。通过具有无序二维组织和三维成分异质性的纤维的顺应层获得分层结构。激光聚合物纤维分层叠加，从有机异质结构的两侧显示出不对称的光学行为，并根据激发方向呈现定制的双色受激发射。通过发光衰减时间测量证明了能量受体分子在确定高能供体物种猝灭中的边际作用。这些发现表明，掺杂不同染料的发光电纺纤维的非织造堆叠表现出临界抑制的Förster共振能量转移，其局限于不同纤维种类之间的连接处。这导致获得具有大部分物理分离的受体和供体的混合材料，从而在很大程度上防止供体猝灭，并使得从多个光谱带同时产生激光变得更加容易。还对该系统进行了相干背散射实验，表明出现了随机激光特征。这些新型有机激光系统可能在需要灵活和双向激发源的微流体装置、光学传感器和纳米光子学中找到应用。
