Abstract

Generation of supercontinuum (SC) was studied experimentally both in water droplets containing silver nanoparticles (NP) in the temperature range from 2 to 22°C and in droplet ice floes frozen to –15°C. It is established that intensity of SC emission exponentially decays along the droplet diameter following excitation by a train of femtosecond laser pulses and linearly increases with increase in NP concentration. Spectrum of SC emission generated in a water droplet containing NPs is investigated in the presence of localized plasmons producing fluorescence in the vicinity of 430 nm. Propagation of a thermal wave along the diameter (d = 1.0 mm) of a small frozen droplet at a speed of 190 mm/s accompanied by exponentially decaying SC emission is discovered. Mathematical model of heat-transfer processes in an ice floe upon thermal-wave formation is proposed.

中文翻译：

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包含银纳米颗粒的水滴在低温下在细丝状态下产生超连续谱

摘要

在温度范围为2至22°C的含银纳米颗粒（NP）的水滴和冷冻至–15°C的水滴浮冰中，都通过实验研究了超连续谱（SC）的产生。已经确定，在飞秒激光脉冲的激励下，SC发射的强度沿液滴直径呈指数衰减，并且随着NP浓度的增加而线性增加。在存在430 nm附近产生荧光的局部等离激元的存在下，研究了在包含NP的水滴中产生的SC发射光谱。热波沿直径（d的传播速度为190 mm / s的冰冻小液滴（= 1.0 mm），伴随着SC的发射呈指数衰减。提出了热波形成过程中浮冰内传热过程的数学模型。