Study of Kerr effect on the transmission of He-Ne laser through atmosphere

Abstract

This work aimed to study the Kerr effect on the transmission of He-Ne laser through atmosphere. Kerr cell was used as a modulator to modulate the signals that had been generated from a signal generator. The cell is made of PLZT-element, and operated by using a power supply with 500 volt. He-Ne laser beam (632.8nm) with power of 1mW was used as a beam carrier. The beam was transmitted through the modulator and then, through the atmosphere to be collected by the receiver at different distances. The divergence of the beam, the signal to noise ratio, transmittance of the beam through atmosphere and the modulation index were measured and calculated. The result of the divergence of the beam was found to be 1.44mrad and the signal to noise ratio was equal to 6.06 at night and at midday it is equal to 2.6; Finally the modulation index at night was found to be 0.525 and at midday was equal to 0.48.This means that the transmittance of the beam at night is greater than at midday.