Abstract: Transmission efficiency and/or spatial resolution provided by resonant apertures can be enhanced by disposing a tip on part of the screen that extends laterally into the aperture. For example, a tip disposed on the ridge of a C-shaped aperture can dramatically improve performance. A spatial resolution of ?/50 has been experimentally demonstrated with this approach. The combination of high spatial resolution and high transmission efficiency provided by this approach enables many applications, such as near field optical probes for near field scanning optical microscopy (NSOM). Another application is high resolution electron sources, where an photoelectron emitter can be disposed at or near a tip+aperture structure such that the high resolution optical near-field provides a correspondingly high resolution electron source.

Abstract: Transmission efficiency and/or spatial resolution provided by resonant apertures can be enhanced by disposing a tip on part of the screen that extends laterally into the aperture. For example, a tip disposed on the ridge of a C-shaped aperture can dramatically improve performance. A spatial resolution of ?/50 has been experimentally demonstrated with this approach. The combination of high spatial resolution and high transmission efficiency provided by this approach enables many applications, such as near field optical probes for near field scanning optical microscopy (NSOM). Another application is high resolution electron sources, where an photoelectron emitter can be disposed at or near a tip+aperture structure such that the high resolution optical near-field provides a correspondingly high resolution electron source.

Abstract: Near-field electromagnetic devices having an opaque metallic screen with a fractal iterate aperture are provided. More specifically, the aperture is obtained by application of a self-similar replacement rule to an initial shape two or more times. Alternatively, the aperture can be obtained by application of a self-similar replacement rule one or more times to an initial C-shape. Such apertures tend to have multiple transmission resonances due to their multiple length scales. Fractal iterate apertures can provide enhanced transmission and improved spatial resolution simultaneously. Enormous improvement in transmission efficiency is possible. In one example, a checkerboard fractal iterate aperture provides 1011 more intensity gain than a square aperture having the same spatial resolution. Efficient transmission for fractal iterate apertures having spatial resolution of ?/20 is also shown.

Abstract: Near-field electromagnetic devices having an opaque metallic screen with a fractal iterate aperture are provided. More specifically, the aperture is obtained by application of a self-similar replacement rule to an initial shape two or more times. Alternatively, the aperture can be obtained by application of a self-similar replacement rule one or more times to an initial C-shape. Such apertures tend to have multiple transmission resonances due to their multiple length scales. Fractal iterate apertures can provide enhanced transmission and improved spatial resolution simultaneously. Enormous improvement in transmission efficiency is possible. In one example, a checkerboard fractal iterate aperture provides 1011 more intensity gain than a square aperture having the same spatial resolution. Efficient transmission for fractal iterate apertures having spatial resolution of ?/20 is also shown.

Abstract: The invention relates to a charging device (10) for the batteries of a cellular telephone, whereby the same device can be used to charge batteries (15) with different external dimensions. The charging device (10) comprises width controllers (19a, 19b), the position of which controls the location and position of the actual battery guides (18a, 18b), which enable batteries of different sizes to get a reliable contact with the electrical connectors (17) of the charging device. Short batteries are locked to the charging device by means of a separate stopper (14).