Experimental far-field imaging properties of high refractive index microsphere lens
The far-field imaging properties of a high index microsphere lens spatially separated from the object are experimentally studied. Our experimental results show that, for a Blu-ray disk whose spacing is 300 nm, the high index microsphere lens also can discern the patterns of the object sample when the distance between the lens and the object is up to 5.4 μm. When the distance is increased from 0 to 5.4 μm, for the microsphere lens with a diameter of 24 μm, the lateral magnification increases from 3.5× to 5.5×, while the field of view decreases from 5.1 to 3.0 μm. By varying the distance between the lens and the object, the optical image can be optimized.We also indicate that the far-field imaging capability of a high index microsphere lens is dependent on the electromagnetic field intensity profile of the photonic nanojet under different positions of the microsphere lens.
基金项目：The authors gratefully acknowledge the financial support for this research from the Doctoral Fund of Ministry of Education of China (No. 20133207110007) and the National Natural Science Foundation of China (No. 61475073).
Yong-Hong Ye：Department of Physics, Nanjing Normal University, Nanjing 210097, China
Jinglei Hou：Department of Physics, Nanjing Normal University, Nanjing 210097, China
Bintao Du：Department of Physics, Nanjing Normal University, Nanjing 210097, China
【1】S. Yang, A. Taflove, and V. Backman, “Experimental confirmation at visible light wavelengths of the backscattering enhancement phenomenon of the photonic nanojet,” Opt. Express 19, 7084–7093 (2011).
【2】P. Ferrand, J. Wenger, and A. Devilez, “Direct imaging of photonic nanojets,” Opt. Express 16, 6930–6940 (2008).
【3】Z. Chen, A. Taflove, and V. Backman, “Photonic nanojet enhancement of backscattering of light by nanoparticles: a potential novel visible-light ultramicroscopy technique,” Opt. Express 12, 1214–1220 (2004).
【4】X. Lopez-Yglesias, J. M. Gamba, and R. C. Flagan, “The physics of extreme sensitivity in whispering gallery mode optical biosensors,” J. Appl. Phys. 111, 084701 (2012).
【5】S. Lee, L. Li, Y. Ben-Aryeh, Z. Wang, and W. Guo, “Overcoming the diffraction limit induced by microsphere optical nanoscopy,” J. Opt. 15, 125710 (2013).
【6】S. Lee, L. Li, and Z. Wang, “Optical resonances in microsphere photonic nanojets,” J. Opt. 16, 15704–15711 (2014).
【7】A. Darafsheh, C. Guardiola, A. Palovcak, J. C. Finlay, and A. Cárabe, “Optical super-resolution imaging by high-index microspheres embedded in elastomers,” Opt. Lett. 40, 5–8 (2015).
【8】E. G. van Putten, D. Akbulut, J. Bertolotti, W. L. Vos, A. Lagendijk, and A. P. Mosk, “Scattering lens resolves sub-100 nm structures with visible light,” Phys. Rev. Lett. 106, 193905 (2011).
【9】V. M. Sundaram and S. B. Wen, “Analysis of deep sub-micron resolution in microsphere based imaging,” Appl. Phys. Lett. 105, 204102 (2014).
【10】K. W. Allen, N. Farahi, Y. Li, N. I. Limberopoulos, D. E. Walker, Jr., A. M. Urbas, and V. N. Astratov, “Super-resolution imaging by arrays of high-index spheres embedded in transparent matrices,” in IEEE Proceedings of National Aerospace and Electronics Conference (NAECON) (2014), pp. 50–52.
【11】L. Lin, W. Guo, Y. Yan, S. Lee, and T. Wang, “Labe-free superresolution imaging of adenoviruses by submerged microsphere optical nanoscopy,” Light Sci. Appl. 2, e104 (2013).
【12】H. Yang, N. Moullan, J. Auwerx, and M. A. Gijs, “Super-resolution biological microscopy using virtual imaging by a microsphere nanoscope,” Small 10, 1712–1718 (2014).
【13】J. Schwartz, S. Stavrakis, and S. R. Quake, “Colloidal lenses allow high-temperature single-molecule imaging and improve fluorophore photostability,” Nat. Nanotechnol. 5, 127–132 (2010).
【14】J. Y. Lee, B. H. Hong, W. Y. Kim, S. K. Min, Y. Kim, M. V. Jouravlev, R. Bose, K. S. Kim, I. C. Hwang, L. J. Kaufman, C. W. Wong, P. Kim, and K. S. Kim, “Near-field focusing and magnification through self-assembled nanoscale spherical lenses,” Nature 460, 498–501 (2009).
【15】Z. Wang, W. Guo, L. Li, B. Luk’yanchuk, A. Khan, Z. Liu, Z. Chen, and M. Hong, “Optical virtual imaging at 50 nm lateral resolution with a white-light nanoscope,” Nat. Commun. 2, 218 (2011).
【16】X. Hao, C. Kuang, X. Liu, H. Zhang, and Y. Li, “Microsphere based microscope with optical super-resolution capability,” Appl. Phys. Lett. 99, 203102 (2011).
【17】A. Darafsheh, G. F. Walsh, L. D. Negro, and V. N. Astratov, “Optical super-resolution by high-index liquid-immersed microspheres,” Appl. Phys. Lett. 101, 141128 (2012).
【18】R. Ye, Y. Ye, H. F. Ma, J. Ma, B. Wang, J. Yao, S. Liu, L. Cao, H. Xu, and J. Zhang, “Experimental far-field imaging properties of a ～ 5 μm diameter spherical lens,” Opt. Lett. 38, 1829–1831 (2013).
【19】R. Ye, Y. Ye, H. F. Ma, L. Cao, J. Ma, F. Wyrowski, R. Shi, and J. Zhang, “Experimental imaging properties of immersion microscale spherical lenses,” Sci. Rep. 4, 1–5 (2014).
【20】D. J. Goldstein, “A quantitative computer simulation of microscopic imaging,” J. Microsc. 162, 241–253 (1991).
【21】D. A. Fletcher, K. E. Goodson, and G. S. Kino, “Focusing in microlenses close to a wavelength in diameter,” Opt. Lett. 26, 399–401 (2001).
【22】D. R. Mason, M. V. Jouravlev, and K. S. Kim, “Enhanced resolution beyond the Abbe diffraction limit with wavelength-scale solid immersion lenses,” Opt. Lett. 35, 2007–2009 (2010).
【23】M. Tsang and D. Psaltis, “Theory of resonantly enhanced nearfield imaging,” Opt. Express 15, 11959–11970 (2007).
【24】M. Tsang and D. Psaltis, “Reflectionless evanescent-wave amplification by two dielectric planar waveguides,” Opt. Lett. 31, 2741–2743 (2006).
【25】Y. Duan, G. Barbastathis, and B. Zhang, “Classical imaging theory of a microlens with super-resolution,” Opt. Lett. 38, 2988–2990 (2013).
【26】T. X. Hoang, Y. Duan, X. Chen, and G. Barbastathis, “Focusing and imaging in microsphere-based microscopy,” Opt. Express 23, 12337–12353 (2015).
Minglei Guo, Yong-Hong Ye, Jinglei Hou, and Bintao Du, "Experimental far-field imaging properties of high refractive index microsphere lens," Photonics Research 3(6), 339-342 (2015)