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arXiv 1808.04076physics.optics
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放大微谐振器无序阵列中的相干随机激射

Coherent random lasing in a disordered array of amplifying microresonators

Anjani Kumar Tiwari

摘要:

在这篇论文中,我们将探讨由放大微共振器所组成的系统所产生的随机雷射。利用蒙特卡罗模拟,研究了光在随机悬浮共振散射体放大介质中的漫射传输。模拟结果表明,单分散散射体在散射体内部区域具有放大作用,可以获得更有效、更稳定的相干随机激光。为了实现这一点,实验上,放大微滴的阵列是使用振动孔液滴发生器创建的。通过改变液滴之间的大小和间距来调整随机性程度。在光激励下,在阵列的纵向方向上观察到相干随机激光。通过使液滴单分散,我们实现了放大平均无规超晶格(aPARS)系统。对aPARS液滴阵列激光波长的统计研究表明,激光峰值只出现在特定的波长区间内。利用光谱模式匹配,我们将模式的频率起伏限制在~ 1.2nm范围内。基于传输矩阵方法的计算表明,实验观察到的激光峰值产生的扰动带边状态的周期系统。液滴阵列中激光模式的空间强度分布证实了其安德森局域性质。我们还考虑微滴阵列作为一个直接耦合的球形微腔的有源链,并检查增益的能力,以克服弯曲和其他辐射损失。

英文摘要:

In this thesis, we explore random lasing from a system comprising of amplifying microresonators. Using Monte-Carlo simulation, we investigate the diffusive propagation of light in an amplifying medium with randomly suspended resonant scatterers. The simulation shows that a more efficient and stable coherent random lasing can be achieved with monodisperse scatterers having amplification in the intra-scatterer region. To realize that experimentally, the array of amplifying microdroplets is created using a vibrating orifice droplet generator. The degree of randomness is tuned by varying the size and spacing between the droplets. Upon optical excitation, coherent random lasing is observed in the longitudinal direction of the array. By making the droplets monodisperse, we realized amplifying periodic-on-average random superlattice (aPARS) system. The statistical study of the lasing wavelengths from aPARS droplet array shows that the lasing peaks occur only within a specific interval of wavelengths. Using spectral mode-matching, we restrict the frequency fluctuation of modes within ~ 1.2 nm. The calculation based on the transfer matrix method shows that experimentally observed lasing peaks arise from the perturbed band-edge states of the underlying periodic system. The spatial intensity distribution of the lasing modes in droplet array confirms its Anderson-localized nature. We also consider the microdroplet array as a direct-coupled active chain of spherical microcavities and examine the ability of gain to overcome the bending and other radiative losses.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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