Hysteresis Loop Effect on Intensity for Horizontal and Vertical Polarization by Optical Feedback

Abstract

The effect of optical feedback on hysteresis loop (HL) is investigated. Hysteresis loop occurs between two eigenstates of the He-Ne laser (x , y) and it changes by optical feedback at angles from 0° to 180°. Hysteresis loop size decreases and increases with the rotation angle (θ) of the polarization. Hysteresis loop effects on vertical (⊥) and horizontal (//) polarization and the intensity for two eigenstates. When HL size increases, then the intensity (I⊥ or I//) decreases vice versa clear. Best results at 70-110 angles from the external cavity (optical feedback cavity), whereas the intensity very high and HL disappear.