Spatial distribution and polarization dependence of the optical near-field in a silicon microfabricated probe |
| |
Authors: | P. N. Minh,T. Ono,S. Tanaka,& M. Esashi&dagger |
| |
Affiliation: | Faculty of Engineering, Tohoku University, AzaAoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan;New Industry Creation Hatchery Center (NICHe), Tohoku University, AzaAoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan |
| |
Abstract: | This paper reports on the spatial distribution and polarization behaviour of the optical near-field at the aperture of a Si micromachined probe. A sub-100 nm aperture at the apex of a SiO2 tip on a Si cantilever was successfully fabricated by selective etching of the SiO2 tip in a buffered-HF solution using a thin Cr film as a mask. The aperture, 10–100 nm in size, can be reproducibly fabricated by optimizing the etching time. The optical throughput of several apertures was measured. For a 100 nm aperture, a throughput of 1% was approved. The probe shows a very high optical throughput owing to the geometrical structure of the tip. The spatial distribution of the near-field light is measured and simulated using a finite difference-time domain method. The polarization behaviour of apertures with different shapes was analysed using a photon counting camera system. |
| |
Keywords: | Aperture FDTD near-field optics NSOM optical throughput polarization probe silicon micromachining. |
|
|