Mach–Zehnder interferometric electro-optic polymer modulators composed of highly nonlinear phenyltetraene bridge-type chromophores within an amorphous polycarbonate host matrix were investigated for their resistance to gamma rays and 25.6 MeV protons. No device failures were observed and the majority of irradiated modulators exhibited decreases in half-wave voltage and optical insertion losses compared to nonirradiated control samples undergoing aging processes. Irradiated device responses were attributed to scission, cross-linking, and free volume processes. The data suggests that strongly poled devices are less likely to de-pole under the influence of ionizing radiation.

The critical angle technique is modified for the accurate measurement of the refractive index of bio-optical materials. Based on the analysis of reflection from the boundary of the material as a function of incident angle and polarization direction, the critical illumination angle is obtained by numerical differentiation of the reflection curve. As an example, the dispersion curve of bacteriorhodopsin is given. The measurement error and the effect of the host bovine skin gelatin on the results are analyzed.

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Empirical data regarding the radiation induced responses of Mach Zehnder interferometric electro-optic polymer based modulators (PBMs) operating at 1310 and 1 550 nm and broadband InP quantum dot (QD) polymer photodetectors (PPDs) operating into the near infrared (NIR) are reported. Modulators composed of spun-on materials and hybrid electostatically self assembled (ESA) and spun-on NLO materials are examined for changes to their half-wave voltage and insertion losses following a gamma-ray total dose of 163 krad(Si) and irradiation by 25.6 MeV protons at a fluence of -1O" cm2. Pre-and post-irradiation responses of ESA grown polymer detectors using InP QDs are examined for photovoltage degradation and aging effects. The data indicates an excellent potential for developing polymer based photonic (PBP) devices with increased radiation resistance suitable for transition to photonic space applications.

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