SRG fabrication

In order to produce surface-relief electro-optic gratings, Munakata et compared two fabrication methods of SRG inscription. In the first, the SRG was produced with an interference pattern of cw laser, with relatively modest intensities. The gratings so recorded were photo- and thermally erasable, and efficient writing was polarization dependent. In the second method, a phase mask was employed to provide the periodic intensity modulation of a pulsed laser, the 3rd-order harmonic (at 355 nm) of a Nd YAG laser. The SRG was produced with a single laser pulse, allowing a very short fabrication time (less than Is). The direshold for ablation was 500 mj/(em pulse), and the amplitude of the SRG increased with pulse energy. A depth of up to 300 rim could be achieved, leading to a smooth but not sinusoidal surface modulation. 

The inscription of SRGs on polymer films also allows for fabricating diffractive optical elements that require intricate surface structxires. For a review of unconventional methods to fabricate and pattern nanostructures, see Xia et Viswanathan et illustrated several such possibilities, such as the honeycomb pattern shown in Figure 14.28, the e -crate-like structure of Figure 14,29, or the beat structure shown in Figure 14.30. These widely... 

When FRP fabrics or sheets are applied on masonry surfaces, the total lack of transpiration that characterizes composite materials should not be neglected. For this reason, the structural reinforcement carried out with such materials should not concern extended surfaces of the wall face, in order to preserve suitable transpiration of the system. The problem of suitable transpiration of masonry supports can be solved by using steel-reinforced grout (SRG) or fiber-reinforced grout (FRG) materials composed of suitably prepared matrices. 

A second important example of technological application is represented by the tensioning system for SRG or SRP fabrics (Fig. 6.8). 

Electronic and photo active polymers such as polyaniline, polyazophenols and poly(l-hydroxypyrene) were synthesized by peroxidase-catalyzed polymerization. These enzymatically synthesized polymers showed interesting electronic and photonic properties. Optical devices such as SRG can be fabricated on the izymatically synthesize polymer thin film. The enzymatic... 

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