Kim, Myun-SikAssafrao, A. C.Scharf, ToralfWachters, A. J. H.Pereira, S. F.Urbach, H. P.Brun, M.Olivier, S.Nicoletti, S.Herzig, Hans Peter2012-11-122012-11-122012-11-12201210.1088/1367-2630/14/10/103024https://infoscience.epfl.ch/handle/20.500.14299/86850WOS:000310437600003We report on the experimental and numerical demonstration of immersed submicron-size hollow focused spots, generated by structuring the polarization state of an incident light beam impinging on a micro-size solid immersion lens (μ-SIL) made of SiO2. Such structured focal spots are characterized by a doughnut-shaped intensity distribution, whose central dark region is of great interest for optical trapping of nano-size particles, super-resolution microscopy and lithography. In this work, we have used a high-resolution interference microscopy technique to measure the structured immersed focal spots, whose dimensions were found to be significantly reduced due to the immersion effect of the μ-SIL. In particular, a reduction of 37% of the dark central region was verified. The measurements were compared with a rigorous finite element method model for the μ-SIL, revealing excellent agreement between them.text::journal::journal article::research article