In order to use infrared windows in the electro-optical systems, which are integrated to the air platforms, its strength and
durability should be high enough for harsh environmental conditions. One of the most challenging environmental
conditions is the rain erosion. An infrared substrate may not continue its necessary functions at high velocity flight under
rain. Special coating techniques should be used for the infrared transparent substrate to increase its durability.
In this study, development of the hard carbon coating, whose substrate material is Germanium, will be discussed. Finite
element analysis of the substrate material will be compared with the rain erosion test data. Test results for the developed
coating will also be presented to show the improvement on durability performance.
In order to determine the vibration effects on performance in optical system, a simple vibratory model is proposed. The
model suggested is compared with FE model. Both models are validated by modal tests for an existing simple optical
system. The material properties of adhesive, which play an imported role in the vibratory model of an optical system, are
found experimentally by using a simple test setup. The model suggested is used to investigate the dynamic behavior of
the optical system under random vibration load conditions. It is concluded in this study that the analytical model
suggested can successfully be used in preliminary design stage of simple optical systems when optical housing and lens
behave rigidly in the frequency range of interest.