In this study, we experimentally demonstrated a flexible random laser fabricated on a polyethylene terephthalate (PET) substrate with a high degree of tunability in lasing emissions. Random lasing oscillation arises mainly from the resonance coupling between the emitted photons of gain medium (Rhodamine 6G, R6G) and the localized surface plasmon (LSP) of silver nanoprisms (Ag NPRs), which increases the effective cross-section for multiple light scattering, thus stimulating the lasing emissions. More importantly, it was found that the random lasing wavelength is blue-shifted monolithically with the increase in bending strains exerted on the PET substrate, and a maximum shift of ∼15 nm was achieved in the lasing wavelength, when a 50% bending strain was exerted on the PET substrate. Such observation is highly repeatable and reversible, and this validates that we can control the lasing wavelength by simply bending the flexible substrate decorated with the Ag NPRs. The scattering spectrum of the Ag NPRs was obtained using a dark-field microscope to understand the mechanism for the dependence of the wavelength shift on the exerted bending strains. As a result, we believe that the experimental demonstration of tunable lasing emissions based on the revealed structure is expected to open up a new application field of random lasers.

中文翻译：

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具有可调激光发射的柔性随机激光器†

在这项研究中，我们通过实验证明了在聚对苯二甲酸乙二醇酯（PET）基板上制造的柔性随机激光器，该激光器在激光发射中具有高度的可调谐性。随机激射振荡主要来自增益介质（若丹明6G，R6G）的发射光子与银纳米棱镜（Ag NPR）的局域表面等离子体激元（LSP）之间的共振耦合，从而增加了多次光散射的有效截面，从而刺激了激光发射。更重要的是，发现随施加在PET基板上的弯曲应变的增加，随机激光波长整体发生蓝移，当弯曲应变为50％时，激光波长的最大偏移达到〜15 nm。施加在PET基材上。这种观察是高度可重复和可逆的，这证明我们可以通过简单地弯曲装饰有Ag NPR的柔性基板来控制激光波长。Ag NPRs的散射光谱是使用暗视野显微镜获得的，以了解波长偏移对施加的弯曲应变的依赖性机理。结果，我们相信基于揭示的结构的可调谐激光发射的实验演示有望为随机激光器开辟一个新的应用领域。