Guided wave materials waveguides

For the ultrasonic guided waves, RTD, thermocouple, and FBG measurement corrcepts the ideal sensor element placement would have been directly in the gas stream. This would have provided the fastest response time, but it also presents the most engineering challenges. An in-stream attachment concept is illustrated in Figure 9-47. Since the sensor wires or waveguide break the pressure boundary, the entry point would be closed by a refractory llnerfcap that would not allow the gas to leak out of the pipe or allow any material to enter the coolant,... 

The fundamental mode of a uniform lossless dielectric waveguide and, in particular, an MNF exists independently of its thickness. However, in practice, wave-guiding is limited by losses due to material absorption and geometric nonuniformities. For a very thin MNF, the transmission loss is primarily determined by input and output losses, which, in practice, cannot be reduced significantly11 64. As an example, Refs. 11 and 13 theoretically explored an MNF with adiabatically... 

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