In spite of their relatively high light absorption rate, polymer materials provide a potent alternative to conventional optical materials due to low-cost, ease of fabrication and assembly, and compatibility with other materials. The recent literature reveals a rapidly increasing interest in the use of polymer components in photonics systems. While polymer waveguides are currently receiving much of the attention, it is to be expected that signal management requirements will lead to progressively

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... greater efforts in gratings, mirrors, and lenses. A Bragg grating (BG) in a light transmitting waveguide produces a very narrow band of reflected optical energy, with a maximum reflectivity at the characteristic wavelength of the grating, called the Bragg wavelength, as illustrated in Figure 2 .1. Unlike the conventional glass fibers, the index of refraction in light-transmitting polymers typically varies inversely with the temperature, leading to negative thermo-optic coefficients that are 10 to 30 times greater than the positive thermo-optic coefficient of conventional silica glass [1]. This strong negative thermo-optical characteristic imbues polymer BGs, generally packaged on low thermal expansion substrates, with precise wavelength discrimination when used as tuning filters. Another important characteristic of polymeric optical materials is their relatively high light absorption rates, at approximately 0.2 dB/cm, as compared to 0.2 dB/km for glass fibers at wavelengths of 1550 nm. However, as shown in Figure 2 .2 for the acrylic-based polymers of allied signal [1], the absorption rates of polymeric optical materials strongly depend on the wavelength. For example, in acrylic with full CH content the absorption rate (0.5 dB/cm) at 1.55 µm is 25 times greater than that at 0.8 µm. Intrinsic self-heating, resulting from these high absorption rates, can produce considerable temperature changes within polymer waveguides and gratings. Such self-heating, as well as the induced temperature gradients and possible changes in the ambient temperature, can cause undesirable shifts in the Bragg wavelength and changes in the reflectivity/transmissivity of the grating. To facilitate the selection of polymeric optical materials