A new sub-wavelength metallic film lens configuration is proposed, which is embedded in a thin ideal metal film, and its near field optical properties are investigated by finite-difference time-domain (FDTD) method. It is found that the optical transmission is greatly enhanced, and the spot size can be reduced by the sub-wavelength metallic film lens in comparison with the bare aperture. This kind of lens is expected to have practical applications in the very small aperture laser (VSAL), a promising nanosource for near-field optical storage and lithography.
© 2005 Chinese Optics Letters
(050.1220) Diffraction and gratings : Apertures
(120.7000) Instrumentation, measurement, and metrology : Transmission
(210.0210) Optical data storage : Optical data storage
(350.6830) Other areas of optics : Thermal lensing
Fei Zhou, Wendong Xu, Yang Wang, and Fuxi Gan, "Optical transmission enhancement by a sub-wavelength film lens," Chin. Opt. Lett. 4, 52-54 (2006)