Water waveguide devices

Selective Response of Polymeric-Film-Coated Optical Waveguide Devices to Water and Toxic Volatile Compounds... 

A typical, experimentally obtained, output spectrum of a waveguide with five resonators of differing sizes is shown in Fig. 16.5a. In this first case, all the five resonators had water as the surrounding medium. As can be seen, each resonator contributes a sharp dip to the output spectrum of the device. We observe that each ID resonator possesses a large -factor varying from 1,500 to 3,000 and a full... 

Fig. 16.5 Response to refractive index interrogation of a single NOSA waveguide, (a) Output spectrum for a NOSA where one of the five resonators is fluidically targeted, first with water and then with a CaCl2 solution. The resonance of the targeted resonator shifts toward the red end of the spectrum due to the higher refractive index of the CaCl2 solution, (b) Experimental data (with error bars indicating inter device variability) showing the redshifts for various refractive index solutions. The solid line is the theoretically predicted redshift from FDTD simulations. The experimental data is in excellent agreement with the theory. Reprinted from Ref. 37 with permission. 2008 Optical Society of America...

We will establish the basic principles that govern the behavior of aU acousto-optic devices whether of bulk or waveguide (SAW) construction. An acousto-optic modulator is composed of an acoustic medium (such as water, glass, lithium niobate, rutile, etc.) and a transducer. The transducer converts electrical signals into sound waves propagating in the acoustic medium with an acoustic frequency spectrum that is limited by the bandwidth of the transducer that matches the electrical excitation. The sound wave causes a perturbation in the index of refraction of the material, setting up a refractive index grating of the form... 

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