Plasmonic resonant nonlinearity and synthetic optical properties in gold nanorod suspensions
We experimentally demonstrate self-trapping of light, as a result of plasmonic resonant optical nonlinearity, in both aqueous and organic (toluene) suspensions of gold nanorods. The threshold power for soliton formation is greatly reduced in toluene as opposed to aqueous suspensions. It is well known that the optical gradient forces are optimized at off-resonance wavelengths at which suspended particles typically exhibit a strong positive (or negative) polarizability. However, surprisingly, as we tune the wavelength of the optical beam from a continuous-wave (CW) laser, we find that the threshold power is reduced by more than threefold at the plasmonic resonance frequency. By analyzing the optical forces and torque acting on the nanorods, we show theoretically that it is possible to align the nanorods inside a soliton waveguide channel into orthogonal orientations by using merely two different laser wavelengths. We perform a series of experiments to examine the transmission of the soliton-forming beam itself, as well as the polarization transmission spectrum of a low-power probe beam guided along the soliton channel. It is found that the expected synthetic anisotropic properties are too subtle to be clearly observed, in large part due to Brownian motion of the solvent molecules and a limited ordering region where the optical field from the self-trapped beam is strong enough to overcome thermodynamic fluctuations. The ability to achieve tunable nonlinearity and nanorod orientations in colloidal nanosuspensions with low-power CW laser beams may lead to interesting applications in all-optical switching and transparent display technologies.
基金项目：Army Research Office (ARO)10.13039/100000183 (W911NF-15-1-0413); National Science Foundation (NSF)10.13039/100000001 (PHY-1404510); National Key R&D Program of China (2017YFA0303800); National Natural Science Foundation of China (NSFC)10.13039/501100001809 (11504184).
Pepito Alvaro：Department of Physics and Astronomy, San Francisco State University, San Francisco, California 94132, USA
Yinxiao Xiang：Department of Physics and Astronomy, San Francisco State University, San Francisco, California 94132, USA
Trevor S. Kelly：Department of Physics and Astronomy, San Francisco State University, San Francisco, California 94132, USA
Yu-Xuan Ren：Department of Physics and Astronomy, San Francisco State University, San Francisco, California 94132, USA
Chensong Zhang：Department of Physics and Astronomy, San Francisco State University, San Francisco, California 94132, USA
Zhigang Chen：Department of Physics and Astronomy, San Francisco State University, San Francisco, California 94132, USATEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin 300457, China
【1】M. Kauranen, and A. V. Zayats, “Nonlinear plasmonics,” Nat. Photonics 6 , 737–748 (2012).
【2】J. Butet, P.-F. Brevet, and O. J. F. Martin, “Optical second harmonic generation in plasmonic nanostructures: from fundamental principles to advanced applications,” ACS Nano 9 , 10545–10562 (2015).
【3】A. S. Reyna, and C. B. de Araújo, “High-order optical nonlinearities in plasmonic nanocomposites—a review,” Adv. Opt. Photon. 9 , 720–774 (2017).
【4】N. C. Panoiu, W. E. I. Sha, D. Y. Lei, and G.-C. Li, “Nonlinear optics in plasmonic nanostructures,” J. Opt. 20 , 083001 (2018).
【5】N. M. Litchinitser, “Nonlinear optics in metamaterials,” Adv. Phys. X 3 , 1367628 (2018).
【6】G. A. Wurtz, R. Pollard, W. Hendren, G. P. Wiederrecht, D. J. Gosztola, V. A. Podolskiy, and A. V. Zayats, “Designed ultrafast optical nonlinearity in a plasmonic nanorod metamaterial enhanced by nonlocality,” Nat. Nanotechnol. 6 , 107–111 (2011).
【7】M. Mesch, B. Metzger, M. Hentschel, and H. Giessen, “Nonlinear plasmonic sensing,” Nano Lett. 16 , 3155–3159 (2016).
【8】Y. Hua, K. Chandra, D. H. M. Dam, G. P. Wiederrecht, and T. W. Odom, “Shape-dependent nonlinear optical properties of anisotropic gold nanoparticles,” J. Phys. Chem. Lett. 6 , 4904–4908 (2015).
【9】M. Gordel, J. Olesiak-Banska, R. Kolkowski, K. Matczyszyn, M. Buckle, and M. Samoc, “Shell-thickness-dependent nonlinear optical properties of colloidal gold nanoshells,” J. Mater. Chem. C 2 , 7239–7246 (2014).
【10】S. Fardad, A. Salandrino, M. Heinrich, P. Zhang, Z. Chen, and D. N. Christodoulides, “Plasmonic resonant solitons in metallic nanosuspensions,” Nano Lett. 14 , 2498–2504 (2014).
【11】T. S. Kelly, Y.-X. Ren, A. Samadi, A. Bezryadina, D. N. Christodoulides, and Z. Chen, “Guiding and nonlinear coupling of light in plasmonic nanosuspensions,” Opt. Lett. 41 , 3817–3820 (2016).
【12】A. S. Reyna, and C. B. de Araújo, “Guiding and confinement of light induced by optical vortex solitons in a cubic-quintic medium,” Opt. Lett. 41 , 191–194 (2016).
【13】J. Trojek, L. Chvátal, and P. Zemánek, “Optical alignment and confinement of an ellipsoidal nanorod in optical tweezers: a theoretical study,” J. Opt. Soc. Am. A 29 , 1224–1236 (2012).
【14】J.-W. Liaw, W.-J. Lo, and M.-K. Kuo, “Wavelength-dependent longitudinal polarizability of gold nanorod on optical torques,” Opt. Express 22 , 10858–10867 (2014).
【15】K. C. Chu, C. Y. Chao, Y. F. Chen, Y. C. Wu, and C. C. Chen, “Electrically controlled surface plasmon resonance frequency of gold nanorods,” Appl. Phys. Lett. 89 , 103107 (2006).
【16】W. Ahmed, E. S. Kooij, A. van Silfhout, and B. Poelsema, “Quantitative analysis of gold nanorod alignment after electric field-assisted deposition,” Nano Lett. 9 , 3786–3794 (2009).
【17】P. Zijlstra, M. van Stee, N. Verhart, Z. Gu, and M. Orrit, “Rotational diffusion and alignment of short gold nanorods in an external electric field,” Phys. Chem. Chem. Phys. 14 , 4584–4588 (2012).
【18】J. Fontana, G. K. B. da Costa, J. M. Pereira, J. Naciri, B. R. Ratna, P. Palffy-Muhoray, and I. C. S. Carvalho, “Electric field induced orientational order of gold nanorods in dilute organic suspensions,” Appl. Phys. Lett. 108 , 081904 (2016).
【19】S. Etcheverry, L. F. Araujo, G. K. B. da Costa, J. M. B. Pereira, A. R. Camara, J. Naciri, B. R. Ratna, I. Hernández-Romano, C. J. S. de Matos, I. C. S. Carvalho, W. Margulis, and J. Fontana, “Microsecond switching of plasmonic nanorods in an all-fiber optofluidic component,” Optica 4 , 864–870 (2017).
【20】M. Maldonado, L. de Souza Menezes, L. F. Araujo, G. K. B. da Costa, I. C. S. Carvalho, J. Fontana, C. B. de Araújo, and A. S. L. Gomes, “Nonlinear refractive index of electric field aligned gold nanorods suspended in index matching oil measured with a Hartmann–Shack wavefront aberrometer,” Opt. Express 26 , 20298–20305 (2018).
【21】Q. Liu, Y. Cui, D. Gardner, X. Li, S. He, and I. I. Smalyukh, “Self-alignment of plasmonic gold nanorods in reconfigurable anisotropic fluids for tunable bulk metamaterial applications,” Nano Lett. 10 , 1347–1353 (2010).
【22】K. C. Ng, I. B. Udagedara, I. D. Rukhlenko, Y. Chen, Y. Tang, M. Premaratne, and W. Cheng, “Free-standing plasmonic-nanorod superlattice sheets,” ACS Nano 6 , 925–934 (2012).
【23】Q. Liu, Y. Yuan, and I. I. Smalyukh, “Electrically and optically tunable plasmonic guest-host liquid crystals with long-range ordered nanoparticles,” Nano Lett. 14 , 4071–4077 (2014).
【24】C. J. Murphy, and C. J. Orendorff, “Alignment of gold nanorods in polymer composites and on polymer surfaces,” Adv. Mater. 17 , 2173–2177 (2005).
【25】J. Pérez-Juste, B. Rodriguez-Gonzalez, P. Mulvaney, and L. M. Liz-Marzan, “Optical control and patterning of gold-nanorod-poly(vinyl alcohol) nanocomposite films,” Adv. Funct. Mater. 15 , 1065–1071 (2005).
【26】J. Li, S. Liu, Y. Liu, F. Zhou, and Z.-Y. Li, “Anisotropic and enhanced absorptive nonlinearities in a macroscopic film induced by aligned gold nanorods,” Appl. Phys. Lett. 96 , 263103 (2010).
【27】K. E. Roskov, K. A. Kozek, W. C. Wu, R. K. Chhetri, A. L. Oldenburg, R. J. Spontak, and J. B. Tracy, “Long-range alignment of gold nanorods in electrospun polymer nano/microfibers,” Langmuir 27 , 13965–13969 (2011).
【28】H. Zhang, Z. Hu, Z. Ma, M. Gecevi?ius, G. Dong, S. Zhou, and J. Qiu, “Anisotropically enhanced nonlinear optical properties of ensembles of gold nanorods electrospun in polymer nanofiber film,” ACS Appl. Mater. Interfaces 8 , 2048–2053 (2016).
【29】M. Pelton, M. Liu, H. Y. Kim, G. Smith, P. Guyot-Sionnest, and N. F. Scherer, “Optical trapping and alignment of single gold nanorods by using plasmon resonances,” Opt. Lett. 31 , 2075–2077 (2006).
【30】C. Selhuber-Unkel, I. Zins, O. Schubert, C. S?nnichsen, and L. B. Oddershede, “Quantitative optical trapping of single gold nanorods,” Nano Lett. 8 , 2998–3003 (2008).
【31】L. Tong, V. D. Miljkovi?, and M. K?ll, “Alignment, rotation, and spinning of single plasmonic nanoparticles and nanowires using polarization dependent optical forces,” Nano Lett. 10 , 268–273 (2010).
【32】P. V. Ruijgrok, N. R. Verhart, P. Zijlstra, A. L. Tchebotareva, and M. Orrit, “Brownian fluctuations and heating of an optically aligned gold nanorod,” Phys. Rev. Lett. 107 , 037401 (2011).
【33】J. Do, M. Fedoruk, F. J?ckel, and J. Feldmann, “Two-color laser printing of individual gold nanorods,” Nano Lett. 13 , 4164–4168 (2013).
【34】Z. Li, W. Mao, M. S. Devadas, and G. V. Hartland, “Absorption spectroscopy of single optically trapped gold nanorods,” Nano Lett. 15 , 7731–7735 (2015).
【35】Y.-X. Ren, T. S. Kelly, C. Zhang, H. Xu, and Z. Chen, “Soliton-mediated orientational ordering of gold nanorods and birefringence in plasmonic suspensions,” Opt. Lett. 42 , 627–630 (2017).
【36】R. Karimzadeh, “Spatial self-phase modulation of a laser beam propagating through liquids with self-induced natural convection flow,” J. Opt. 14 , 095701 (2012).
【37】R. El-Ganainy, D. N. Christodoulides, C. Rotschild, and M. Segev, “Soliton dynamics and self-induced transparency in nonlinear nanosuspensions,” Opt. Express 15 , 10207–10218 (2007).
【38】R. El-Ganainy, D. N. Christodoulides, E. M. Wright, W. M. Lee, and K. Dholakia, “Nonlinear optical dynamics in nonideal gases of interacting colloidal nanoparticles,” Phys. Rev. A 80 , 053805 (2009).
【39】W. Man, S. Fardad, Z. Zhang, J. Prakash, M. Lau, P. Zhang, M. Heinrich, D. N. Christodoulides, and Z. Chen, “Optical nonlinearities and enhanced light transmission in soft-matter systems with tunable polarizabilities,” Phys. Rev. Lett. 111 , 218302 (2013).
【40】L. Novotny, and B. Hecht, “Forces in confined fields,” in Principles of Nano-Optics (Cambridge University, 2006), Chap.?13, pp.?427–428.
【41】Q. Zhan, “Trapping metallic Rayleigh particles with radial polarization,” Opt. Express 12 , 3377–3382 (2004).
【42】P. M. Hansen, V. K. Bhatia, N. Harrit, and L. Oddershede, “Expanding the optical trapping range of gold nanoparticles,” Nano Lett. 5 , 1937–1942 (2005).
【43】F. J. V. Santos, C. A. Nieto de Castro, J. H. Dymond, N. K. Dalaouti, M. J. Assael, and A. Nagashima, “Standard reference data for the viscosity of toluene,” J. Phys. Chem. Ref. Data 35 , 1–8 (2006).
【44】J. W. P. Schmelzer, E. D. Zanotto, and V. M. Fokin, “Pressure dependence of viscosity,” J. Chem. Phys. 122 , 074511 (2005).
Huizhong Xu, Pepito Alvaro, Yinxiao Xiang, Trevor S. Kelly, Yu-Xuan Ren, Chensong Zhang, and Zhigang Chen, "Plasmonic resonant nonlinearity and synthetic optical properties in gold nanorod suspensions," Photonics Research 7(1), 28-35 (2019)