الفهرس 
1.1. Optical Communication SystemOnly 14 pages are availabe for public view
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Abstract
In this thesis the effect of ionizing radiation on fiber optic communication System investigated. The governing equations of the optical performance of the three parts of the system namely: Source (VCSELs), Link (Optical fiber cables) and Detector (APDs) exposed to radiation environment are modeled using block diagram programming approach. Different types of radiation are treated according to its importance and harmful effects to a specific part of the system. The study findings associated with each part of the system can be stated as follows: Source (VCSELs): In this work we have demonstrated the optical performance degradation of VCSELs in thermal irradiation environment. We illuminate the effect of those environments on VCSELs efficiency, transient temperature increase, power dissipation (ΔP), change of device temperature (ΔT), threshold current (Ith). Link (Optical fiber cables): The effects of ionizing radiation on optical fiber cables can be conclude in three main evils: a. Radiation induced attenuation (RIA) in optical fibers. b. The other significant destructive effect of radiation on optical fibers is that the radiation induced luminescence in fibers which results from the Cherenkov process occurring within the fibers. c. The third vital harsh effect is that radiation and temperature influence the optical fiber characteristics. In this part we present a block diagram models and a simulation results of the radiation induced transmission loss, radiation induced light, and radiation induced optical fiber characteristics change by using VisSim environment to provide a mean to control the optical fiber properties in radiation environments. Detector (APDs): In this part a block diagram model treating the radiation induced damage is proposed to provide a mean to control the optical properties of APDs in thermal radiation environments. The proposed treatment can be used to improve the detectivity, noise equivalent power, and the normalized detectivity. And to reduce thermal radiation effects, the results showed that this can be achieved by minimizing the active device volume. In the same time this provides higher detector sensitivity and responsibility as well as detector efficiency.