title: Subwavelength-size solid immersion lens.
abstract: We report on the fabrication and characterization of nanoscale solid immersion lenses (nano-SILs) with sizes down to a subwavelength range. Submicrometer-scale cylinders fabricated by electron-beam lithography are thermally reflowed to form a spherical shape. Subsequent soft lithography leads to nano-SILs on transparent substrates for optical characterization. The optical characterization is performed using a high-resolution interference microscope with illumination at 642 nm wavelength. The focal spots produced by the nano-SILs show both spot-size reduction and enhanced optical intensity, which are consistent with the immersion effect.
authors.affiliation: Optics & Photonics Technology Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), Breguet 2, 2000 Neuchâtel, Switzerland. myunsik.kim@epfl.ch
authors.forename: Myun-Sik
authors.initials: MS
authors.lastname: Kim
authors.forename: Toralf
authors.initials: T
authors.lastname: Scharf
authors.forename: Mohammad Tahdiul
authors.initials: MT
authors.lastname: Haq
authors.forename: Wataru
authors.initials: W
authors.lastname: Nakagawa
authors.forename: Hans Peter
authors.initials: HP
authors.lastname: Herzig