Effect of thickness on the fractal optical modulator for MgF2,LiF, AL2O3 materials by testing modulation transfer function (MTF)

The optical modulator or chopper is an important component in optical systems. It is a device, which changes the angle between the vision line of the target and the coordinate of an electrical signal. This paper has been designed as a new model of the fractal optical modulator. A new optical modulator involves two cycles (inner and outer). Each cycle of them consists of eighteen sections. It is known that the sections of the optical modulator become two parts, nine sections considered are transparent and the other sections are opaque to light. There are two parameters have taken to design the optical modulator, first factor is the shape and second factor is the section number. A new optical modulator is made from three materials such as (Magnesium Fluoride (MgF2), Lithium Fluoride (LiF) and Sapphire (Al2O3) by using the fractal function. So an optical modulator is created by building a computer program using the visual basic language. For the importance of the modulation transfer function (MTF) in testing and evaluating optical systems, the dependent measurement is done to know the optical systems efficiency. It has been studied the optical systems with a circular aperture, where that function could be evaluated the image efficiency for point object of image plane at different magnitude of the wavelength and thickness. In this research, the fractal optical modulator has been designed of insulator material by using the fractal function. It has been evaluated the values of MTF at different values of the wavelength and thickness. Also, we studied the relation between spatial frequency and number of sections, as well.