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A scanned probe above a charged surface was investigated to determine electrostatic force density.

In this paper, we describe a way to achieve the extraordinary transmission regime well into the UV range using subwavelength slits carved on semiconductor substrates. Unlike metals, the dielectric permittivity of typical semiconductors like GaAs or GaP is negative beginning in the extreme UV range (λ≤270 nm) and is characterized by large absorption. We show that the metallike response of bulk semiconductors exhibits surface plasmon waves that lead to extraordinary transmission in the UV and soft x-ray ranges, in spite of the large absorption. The importance of realistic material response versus perfect conductors is also discussed. We show that the use of perfect conductor boundary conditions can lead to field amplitudes that may be underestimated by several orders of magnitudes. These findings may be important in high resolution photolithography, near-field optical devices, and ultrahigh density optical storage in wavelength ranges, where it may not be possible to utilize more traditional plasmonic materials like noble metals. [ABSTRACT FROM AUTHOR]

We present a demonstration of the surface plasmon phenomenon as it occurs in thin metal island films. The metal films are deposited on glass microscope slides. The effect of the surface plasmon resonance may be observed visually on the slide without further apparatus. Heating the film changes the shape of the islands and therefore the resonant frequency of the surface plasmon and changes the color of the film. Placing the film in a dielectric medium changes the resonance condition for the surface plasmon again and changes the color again. We show this by coating the slides with commercially available liquids with different indices of refraction. We present a theoretical model that assumes the islands are oblate spheroids. There are enough details given so that the equations can be programed and the theoretical optical absorbance can be reproduced. We also present a modification to the theory so that the shift in resonant frequency can be calculated when the spheroids are immersed in the index fluids. We describe our apparatus for making thin films and our optical spectrometer system. We then present optical absorbance measurements of thin films of both Ag and Au in air and in two liquids with different indices of refraction. [C] 2000 American Association of Physics Teachers.