Optically transparent waveguide

This chapter describes the synthesis of partially fluorinated polyimides for optical teleconununications applications," " 2 their optical transparency (optical loss), refractive index, and birefringence properties" in addition to their fundamental properties. It also describes their device application as optical interference filters," " optical waveplates," and optical waveguides." -" ... 

Low-loss, heat-resistant single-mode optical waveguides were fabricated using the fluorinated copolyimides with a high optical transparency and refractive index controllability. The high thermal stability of these waveguide materials... 

Reagents and indicators are immobilized, occluded or dissolved in supports which are formed by cross-linked polymers, plasticized polymers or organic and inorganic activated surfaces. The waveguide itself, the cladding of an optical fiber or any other optical element can be the support. However, it must obey two basic functions act as a liquid-solid or gas-solid interface and, if radiation crosses through it to allow the signal transmission, be an optically transparent material. 

There are two major types of planar waveguides - those with a graded index and those that are step-indexed, as shown in Fig. 4. Waveguides can be composed of any optically transparent material such as glassy materials and polymers, depending on their structure. 

Multifunctional materials will play an important role in the development of Photonics Technology. This paper describes novel multifunctional polymeric composites for applications in both active and passive photonic components. On the molecular level, we have introduced multifunctionality by design and synthesis of chromophores which by themselves exhibit more than one functionality. At the bulk level, we have introduced the concept of a multiphasic nanostructured composites where phase separation is controlled in the nanometer range to produce optically transparent bulk in which each domain produces a specific photonic function. Results are presented from the studies of up-converted two-photon lasing, two-photon confocal microscopy, optical power limiting, photorefractivity and optical channel waveguides to illustrate the application of the multifunctional optical composites. 

Optically transparent Pis are also of special importance for optoelectronic devices such as optical waveguides for communication interconnects and optical half-waveplates for planar lightwave circuits. 

Figure 7. Equipment geometries for studying the wave and acousto-electrical interactions in nematics (1) substrate (y cut, x oriented quartz), (2) glass plate, (3) interdigital transducer, (4) shear transducer (y cut quartz), (5) compression transducer (x cut quartz), (6) nematics, (7) mirror coating, (8) optically transparent electrode, (9) generator, (10) waveguide (substrate), (11) phase meter.

Transparent materials nanocomposites with high refractive index (w 1.65-1.79) and high transparence in visible light region, with transmittance higher than 90%, are potential materials for fabrication of optical fibers, waveguides, lenses, and LED packages [7]. 

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