Waveguide techniques

The CEM Discover platform, introduced in 2001, offers a single-mode instrument based on the self-tuning circular waveguide technique (see Fig. 3.3). This concept allows for derivatization of the reactor to accommodate additional application-specific modules to address other common laboratory objectives. While the Discover ... 

This study represents the first systemmatic application of the optical waveguide technique to the study of the response of polymer film coatings to condensed vapor molecules. These results indicate that the technique is useful for surveying rapidly potential polymeric films as possible vapor sensor coatings. Moreover, this work has further substantiated that the vapor pressure is an important physical property to be taken into account when employing polymeric films as surface coatings. 

Such surfaces can exhibit enhancements up to two orders of magnitude. Also ATR configurations can be used on a variety of sur-faces. " Interference techniques can be applied as well as waveguide techniques in 100-nm films. New geometries for surface enhancement were suggested, for instance by Aravind et... 

If the stiffness is negligible, then the simple delay-based waveguide techniques can be extended to two dimensions as shown in Figure 12.4. As discussed in... 

EUipsometiy allows the optical properties of thin layers at electrode surfaces to be smdied as a function of wavelength, time, and potential. Theoretictil models allow conclusions about the film thickness and stmcture. Optical waveguide techniques improve the interaction of the electromagnetic wave with the sample for example in surface plamon resonance processes. 

V6r6s J, Graf R, Kenausis GL, Bruinink A, Mayer J, Textor M, Wintermantel E, Spencer ND. Feasibility study of an online toxicological sensor based on the optical waveguide technique. Biosens. Bioelectron. 2000 15 423-429. 

Fitting Eq. 2 to our data yields an adsorbed polymer mass r 200 100 ng/cm, which is in good agreement with the typical adsorbed mass of this PLL-g-PEG architecture on various metal oxide substrates, as determined from an optical waveguide technique (180 20 ng/cm ) (Kenausis et al., 2000 Pasche et al., 2003). 

The thickness and the refractive index of the polymer film can also be measured more precisely by optical waveguiding techniques. The planar wave guide technique in which the light is confined in one direction only is widely used for this purpose Table 1 summarizes some of the linear optical properties of photoreactive polymer films. 

The filters were designed for operation at 530 nm, and preliminary estimates for monolayer thickness I and refractive index Wq for both materials were obtained by ellipsometry, reflectometry and waveguiding techniques (Table 3.2). Reasonable agreement was obtained between these techniques, particularly for the polysiloxane. The thickness and refractive index data were then refined to give more accurate initial layer thickness f and refractive index values (Table 3.3) by taking account of the dispersion of the materials over the wavelenth range 400-800 nm (Fig, 3.12). 

CO very time Ton with pulse voltage is quite unexpected, and suggests that complex patterns of molecular rotation may be excited by the interdigital electrodes. Such effects are relevant to display-device technology, and optical-waveguide techniques appear to be an advantageous way of studying them. 

Figure 4.6 The feedback interaction between the source and the resonator is an important aspect of the waveguide technique...

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