Solid hemispherical lenses

The emitted photo electrons are collected by an electron optical device from a solid angle significantly wider than defined by the entrance aperture of the analyzer. Modern instruments use sophisticated lens systems allowing the imaging of the sample by the photoelectrons. The hemispherical analyzer is an electro-... 

Past strategies for increasing the storage capacity of optical disks were based on a reduction of A and an increase in NA, as can be seen from Table 12.1. In principle, a reduction in the spot size can be achieved with the aid of solid immersion lenses. This as yet not practically exploited technique, operating with a hemispherical or a Weierstrass superspherical lens placed near the recording medium (< 100 nm), yields a reduced spot size, S, as is evident from Eqs. (12-2) and (12-3), respectively, where n denotes the refractive index of the lens [8],... 

Figure 7 shows two designs of coverslip-form solid-immersion micropshere superlens we have proposed, a flat-top design (Fig. 7a), and a hemisphere-top design (Fig. 7b), both having a thickness similar to standard coverslip which is small enough for the superlens to be directly inserted into the gap between conventional microscope s objective lens and sample. The hemisphere-top curved surface in the design Fig. 7(b) is used to reduce the effect of total internal reflection from a flat surface. 

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