OPTIMAL DESIGN OF APERIODIC OPTICAL SUPERLATTICES FOR ACHIEVING PARAMETRIC AMPLIFICATION OR SECOND HARMONIC GENERATION WITH CONSIDERATION OF THE DEPLETION OF PUMPING LIGHT POWER

The parametric amplification (PA) and second harmonic generation (SHG) from quasi-one-dimensional aperiodic optical superlattices (AOSs) are investigated in the cases of large, intermediate, and small signals of the pumping light wave. The optimal design of the AOSs is carried out with the use of the simulated annealing (SA) method. The numerical simulations show that the constructed AOSs can achieve multiple wavelength PA (or SHG) with identical amplification (or identical conversion efficiency) at the pre-assigned wavelengths. The variations of the normalized intensities of the PA signal (or the pumping fundamental wave (PFW)) for the PA process with the distance of propagation of the light wave from the interface of the AOSs at the pre-assigned wavelengths exhibit monotonically increasing (or decreasing) behavior. So do the variations of the normalized intensities of the second harmonic wave (SHW) (or the fundamental wave (FW)) for the SHG. This strongly supports the fact that the contribution of each individual unit domain in the constructed samples to the PA (or SHG) is constructive accumulation, favorable for the PA (or SHG) process. The saturation phenomenon of the PA (or SHG) signal is observed.