Exploitation of electric field assisted optical signal amplification in ferroelectric photorefractive K0.50Na0.50NbO3 thin film

Abstract The exploitation of non-linear optical property of potassium sodium niobate [KxNa1-xNbO3 (x = 0.50 or KNN-50)] thin film using the two-wave mixing technique in the presence of an external electric field has been performed for the first time. The results show that the presence of external electric field enhances the non-linear optical activity in the KNN-50 medium. For this study, the KNN-50 thin film was prepared on fused quartz substrate by pulsed laser deposition (PLD) technique. XRD study confirms the formation of perovskite phase, and the FESEM image supports the growth of densely packed micro-structured KNN-50 thin film. The band gap of 800 nm thick KNN-50 thin film was found to be 4.1 eV. The electric field assisted nonlinear optical studies are promising, and opens large opportunity of incorporation of these KNN-50 thin films in the development of non-linear optical devices.