Waveguide devices

K. Saha, F. Bender, and E. Gizeli, Comparative study of IgG binding to proteins G and A nonequilib-rium kinetic and binding constant determination with the acoustic waveguide device. Anal. Chem. 75, 835-842 (2003). 

For the practical application to nonlinear optics, further, noncentrosymmetric LB films are required to possess not only large nonlinear optical response but excellent optical quality and thickness appropriate to optical devices. In this study, a family of pyrazine derivatives was found to be an LB film-forming material applicable to waveguide devices. The optical nonlinearity in the pyrazine LB films and the application of the pyrazine LB films to a frequency-doubling waveguide device is demonstrated in the latter part. 

Figure 16 shows the dependence of the SH intensity at 45° incidence of p-polarized fundamental light on the number of deposited bilayers. The SH intensity increases quadratically with the film thickness of up to 400 bilayers (2 pm), as predicted theoretically in the case of the nonlinear slab with a thickness much smaller than the coherence length. The quadratic dependence demonstrates that the highly ordered noncentrosymmetric molecular orientation, which was confirmed in the relatively thin LB film from the SHG and X-ray diffraction measurements, was preserved in the alternating LB film with the thickness enough to be applied to the nonlinear waveguide devices. 

Using the refractive index value of the pyrazine LB film, we calculated the mode dispersion curves of the TM fundamental and the TM second-harmonic waves in the waveguide device composed of a waveguiding pyrazine layer and a fused quartz substrate when Nd YAG laser is used as a fundamental light (Fig. 18). These curves show that the Cerenkov type phase matching is possible in the range of the thickness from 410 nm to 510 nm. 

A. Sudbo and P.I. Jensen, Stable bidirectional eigenmode propagation of optical fields in waveguide devices, Integrated Photonics Research, 27-29 (OSA, Monterey, 1995). 

J. M. Hammer, et al., Isolators, polarizers and other optical waveguide devices using a resonant-layer effect, Journal Lightwave Technology 22, 1754-1763 (2004). 

Crosslinkable polymethacrylate copolymers, (III), prepared by Yamamoto (6) were effective as optical waveguide devices. 

Lytel, R. Lipscomb, F. Electro-Optic Polymer Waveguide Devices Status and Applications, this volume... 

Figure 2 shows the tradeoffs between crystal and polymer organic NLO materials for device applications. Although cither type of materials could in principle be used for both applications, crystals are best for second harmonic generation, and poled polymers are best for electro-optic waveguide devices such as modulators and switches. 

Figure 2. Tradeoffs between polymer and crystal organic nonlinear optical materials. EO refers to applications for electro-optic waveguide devices such as modulators and switches. SHG refers to applications for frequency doubling of moderate and low power laser sources. A + indicates favored, - indicates disfavored, 0 indicates neither favored nor disfavored, and x indicates not relevant.

Input couplings for all waveguide devices were performed by grating couplers. 

Conceptual structure of the four-layered waveguide device is depicted in Fig 7. In figure dashed trapezoidal pattern was surrounded by grating. This is a method to realize appropriate wave-guiding for various vacuum evaporated PDA film. Experimental setup for all optical bistability with a pulsed Nd YAG laser 1064 nm is shown in Fig 8. 

These materials may also be included in guest-host or side-chain polymer systems, similar to those exploited in electro-optic polymer studies. This would improve processability for waveguide devices. The coefficients quoted above show that such a doped polymer could function at reasonable power levels and waveguide dimensions with an active region 1-2 mm long. 

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

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