Widely Tuning Surface Plasmon Polaritons with Laser-Induced Bubbles

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• 作者：Fengyuan Gan ; Yujia Wang ; Chengwei Sun ; Guorui Zhang ; Hongyun Li ; Jianjun Chen and Qihuang Gong
• 刊名：Advanced Optical Materials
• 出版年：2017
• 出版时间：February 16, 2017
• 年：2017
• 卷：5
• 期：4
• 全文大小：1760K
• ISSN：2195-1071

文摘

The wide-range tunable all-optical plasmonic devices are of importance for the multifunctional photonic circuits of high densities. Here, the laser-induced bubbles are utilized to widely tune the surface plasmon polaritons (SPPs) in the metallic hole array. Because of the bubbles generation under a pump beam, the equivalent refractive index of the dielectric medium adjacent to the metal surface decreases. This decrease blue-shifts the transmission spectrum of the hole array. Experimentally, a modulation depth of 18 dB below the critical pump intensity and an index variation of Δn = −0.333 corresponding to a wavelength shift of about Δλ = −200 nm above the critical pump intensity are achieved. Moreover, the transmission intensity at λ = 870 nm can be tuned to cover the whole range from the peak intensity to the valley intensity of the hole array by controlling the size of the bubble. Such a large index variation (Δn = −0.333) and wavelength change (Δλ ≈ −200 nm) can greatly decrease the designing difficulty of the tunable plasmonic devices. Thus, the laser-induced bubbles under low pump intensities may find important applications, such as efficient modulating as well as tunable color filter, focusing, and imaging with broadband responses.