报告题目：The Wonderful World of Random Lasers and Random Fiber Lasers

主讲人：Anderson S. L. Gomes  巴西科学院院士  巴西伯南布哥联邦大学

时    间：2024年6月21日14:30

地    点：安徽大学磬苑校区材料大楼A401

主办单位：物理与光电工程学院

欢迎各位老师、同学届时前往！

报告摘要：

Random Lasers (RLs) are coherent light sources whose feedback mechanism relies on light scattering in a strongly scattering media in the presence of a gain medium, instead of a pair of fixed mirrors. Upon appropriate pumping, inversion population and amplification precede the optical feedback such as the gain overcomes the loss as in conventional lasers. As reviewed in [1], where most of the historical background and theoretical/experimental developments until June 2021 can be read, RLs, as well as Random Fiber Lasers (RFLs) have become an important tool for photonic studies. As light sources, RLs and RFLs have been demonstrated in all 1D, 2D and 3D configurations, and well characterized regarding threshold, line narrowing/emitted intensity versus excitation intensity, polarization, spatial and temporal coherence, photon statistics (which has been shown to be Poissonian) and operation in the continuous wave or pulsed regime. Regarding RL materials, as long as there is a suitable gain medium (dye, rare earth doped glasses and crystals, semiconductors, quantum dots, etc) and a scattering medium (which can be the same as the gain medium or external to it) a myriad of RLs/RFLs have been demonstrated [see ref. 1]. As for RFLs, even the Rayleigh scattering in a few tens of meters fiber length is enough to provide optical feedback, and intrinsic Raman or Brillouin processes provide the gain for laser action, which also supports transform limited mode-locked pulses [2]. Regarding applications, RLs and RFLS have been exploited for speckle-free imaging, which is an important feature for diagnostic by imaging. In optical communications, RFLs optical amplifiers have been demonstrated to perform better than conventional optical fiber amplifiers, as reviewed in [1] and refs therein. RLs and RFLs have been exploited as a photonic platform to study, by analogy, turbulence, photonic spin glass, Lévy statistics, Floquet states and extreme events. The connection between photonic turbulence and spin glass behavior of light has shown to bridge the two subjects and, through experiments using RFLs, have been highlighted in connection with recently awarded 2021 Nobel Prize in Physics [3]. In a recent collaborative work between our group at UFPE and the Anhui University group, the observation of the photonic Hall effect in random fiber laser has been reported [4].

All these exciting features of the wonderful world of RLs and RFLs will be touched upon during this lecture.

References

[1] Anderson S.L. Gomes, André L. Moura, Cid B. de Araújo and Ernesto P. Raposo, (Review) Recent advances and applications of random lasers and random fiber lasers, Progress in Quantum Electronics 78, 100343 (2021).

[2] Jean Pierre von der Weid, Marlon M. Correia, Pedro Tovar, Anderson S. L. Gomes & Walter Margulis, A mode-locked random laser generating transform-limited optical Pulses, Nature Communications 15:177 ( 2024).

[3] A. S. L. Gomes, C. B. de Araújo, A. M. S. Macêdo, I. R. R. González, L. de S. Menezes, P. I. R. Pincheira, R. Kashyap, G. L. Vasconcelos and E. P. Raposo “Photonics bridges between turbulence and spin glass phenomena in the 2021 Nobel Prize in Physics,” Light: Science & Applications 11:104 (2022).

[4] Wenyu Du, Lei Hu, Jiangying Xia, Lin Zhang, Siqi Li, Yan Kuai, Zhigang Cao, Feng Xu, Yu Liu, Kaiming Zhou, Kang Xie, Benli Yu, Ernesto P. Raposo, Anderson S.L. Gomes, Zhijia Hu, Observation of the photonic Hall effect and photonic magnetoresistance in random lasers, Nature Communications 15, 4589(1-10) 2024.

报告人简介：

Anderson Stevens Leônidas Gomes，巴西科学院院士，巴西伯南布哥联邦大学物理系教授。1978年和1982年在伯南布哥联邦大学物理系获得本科和硕士学位，1986年在帝国理工学院获得激光物理学博士学位，1992年在美国布朗大学从事博士后研究。研究领域为激光在纳米和生物光子学、非线性光学和非线性光子器件中的应用。与他人合作发表300多篇论文，H指数为48。指导硕士论文39篇，博士论文20篇。曾获巴西国家科学技术发展委员会1A级奖学金，是OPTICA(前OSA)会士，并担任国际理事会主席(2011-2012)。曾担任巴西东北部区域副主席(2022/2023)，是世界科学院(TWAS)、巴西物理学会(SBF)和巴西科学促进会(SBPC)的成员。曾在伯南布哥担任科学和技术国务秘书(2010年)和教育国务秘书(2011/2012年)。2010年被授予国家科学功绩勋章，2023年7月被授予物理科学领域的格兰克鲁兹总统奖。