Resonator designs

Figure 2 shows a specific example of the effect on a C-13 n.m.r. spectrum when the sample temperature is changed. With increasing temperature the resonances are displaced down-field and become more narrow. The upper plot of Figure 2 shows the linear A5/AT for the resonances designated in the spectra. The dextran anomeric AT effects are even greater than the selected example shown in Figure 2. 

Figure 5.8 Typical planar resonators being used as building blocks for filters lumped element (a), microstrip (b), folded microstrip with integrated capacitors (c), coplanar (d), and 2-D microstrip resonator. Omitting the capacitive gap in the folded microstrip design (c) leads to a ring resonator (square if circular shaped), which also represents a quite commonly used microstrip resonator design.

Melting Transition Typical 360 MHz proton NMR spectra of proflavine poly(dA-dT) complexes, Nuc/D = 24 and Nuc/D = 8, in 1 M NaCl solution at temperatures below the midpoint for the dissociation of the complex are presented in Figures 17A and B respectively. The stronger base and sugar resonances can be readily resolved from the weaker proflavine resonances (designated by asterisks) in the presence of excess nucleic acid (Figure 17) so that the resonances of the synthetic DNA and the mutagen can be monitored independently of each other. 

Figure 25. The 360-MHz correlation proton NMR spectra of the daunomycin poly(dA-dT) complex in /M NaCl, lOmNi cacodylate, lOmM EDTA, 80% HaO— 20% 2H 20. Spectrum A corresponds to the Nuc/D = 11.8 complex, pH 6.0 at 67°C and Spectrum B corresponds to the Nuc/D = 5.9 complex, pH 6.05 at 57°C. The strong resonance corresponds to thymidine H-3 proton of the nucleic acid while the weaker resonances (designated hy asterisks) corresponds to hydroxyl protons at Positions 9 and 11 on Ring B of the anthracycline ring of daunomycin...

A DNA biosensor based on various porous silicon layers was fabricated using an oxidized microcavity resonator design developed by Chan et al. [37], the porous sihcon containing silicon nanocrystals that can luminescence efficiently in the visible. 

Another advantage of our approach over other optical resonator designs is its suitability for performing multiplexed detections. Due to the fabrication process and the planar nature of the device, it is easy to fabricate a single... 

A high resolution study of the Vj band of HCN at 3 )un has been recently reported using a standard small volume cell of non-resonant design . The 25 lowest rotational levels of the V3 band were excited with a tunable < lor center laser at an HCN pressure of 20 m Torr. The pressure of the N2 buffer gas was varied between 20 and 400 Torr to investigate pressure broadening and to detect possible frequency shifts induced by the buffer gas. In intracavity experiments performed at an HCN pressure of only 0,02 mTorr no shift of the transition frequency could be detected, to the accuracy of the wavemeter readout. The results of this photoacoustic analysis of the V3 band of HCN are ... 

In order to improve on the spectral purity, i.e. reliable single-mode operation of diode lasers, their resonator design needs to be altered. Both of the common solutions work on grating-induced wavelength-selective feedback. 

Fig. 5.78a,b. Two possible resonator designs for cw color-center lasers (a) folded linear resonator with astigmatic compensation and (b) ring resonator with optical diode for enforcing only one direction of the traveling laser wave and tuning elements (birefringent filter and etalon) [5.145]... 

Various pumping geometries and resonator designs have been proposed or demonstrated [5.151]. In transverse pumping (Fig. 5.83), the pump laser beam is focused by a cylindrical lens into the dye cell. Since the absorption coefficient for the pump radiation is large, the pump beam is strongly attenuated... 

Fig. 5.84. Possible resonator designs for longitudinal pumping of dye lasers [5.151]...

A HeNe laser with an unsaturated gain of Go(vo) = 1.3 at the center of the Gaussian gain profile has a resonator length of J = 50 cm and total losses of 4%. Single-mode operation at vq is achieved with a coated tilted etalon inside the resonator. Design the optimum combination of etalon thickness and finesse. 

The mode structure discussed previously has been developed assuming rectangular-shaped electrodes. Most high-frequency resonators, however, use flat or spherical circular electrode shapes. The electrode shapes affect the boundary conditions for the mode vibrations, and the resulting resonant frequencies must now be described by mathematical functions that are able to satisfy those boundary conditions. For example, with flat circular electrodes, Bessel functions are used to describe the resonant mode behavior. Spherical contoured plates are also routinely appHed to resonator designs. 

---