Tunability of third order nonlinear absorption in (Pb,La)(Zr,Ti)O3 thin films

Nonlinear optical absorption tuning in Bi3.15Nd0.85Ti3O12 ferroelectric thin films by thickness

“…Based on the above results, it is observed that the SA-to-RSA switching has been realized by changing the BNT film thickness, which is different from the single NLO absorption type of ferroelectric thin films surveyed in previous reports. 18,[21][22][23] The similar SA-to-RSA switching phenomenon has already been found in noble metal nanoparticles 8-10 and nanocrystalline Si films. [11][12][13] Generally, this switching phenomenon is considered to be the consequence of the competition between the ground-state excitation and the nonlinear absorption, which is critically dependent on the laser photon energy, the intensity of the incident radiation, and the band-gap energy of materials.…”

“…Such a SA phenomenon can be used as an ultra-fast optical modulation in the laser oscillator to generate an ultra-short pulse laser, 31 which is seldom reported in ferroelectric thin films. 18,[21][22][23] Interestingly, when the thickness increases to 139.7 nm, the NLO absorption type evolves into RSA (shown in Fig. 3(b)), which is a typical characteristic for optical limiting phenomena and useful for applications of protecting optical sensors from intense laser pulses.…”

“…22 Ambika et al have tuned the third-order nonlinear absorption in Pb(Zr,Ti)O 3 films by changing the La doping concentration. 23 However, the NLO absorption type in most ferroelectric thin films is still limited to RSA 18 and the boundary between SA and RSA is seemingly hard to break through. For the wider photonic application of ferroelectric thin films, a simple and effective modulation method is urgently needed to clear away the obstacle.…”

“…Additionally, the density of defect states in the band-gap can directly relate to the transformation process for their ability to modulate the competition between SA and RSA in the defect-mediated mechanism. 23 The NLO absorption responses of BNT thin films with different thicknesses were investigated by the open aperture Z-scan method. The results demonstrate a thickness-related NLO tunability in BNT films that the NLO absorption process can be switched from SA to RSA with the thickness increase.…”

Linear and Nonlinear Optical Properties of Ferroelectric Thin Films

“…The ions (Pb, Mn, or K) dopant as the acceptor in ferroelectric films could reduce the dielectric loss and enhance the third-order optical nonlinearity (Zhang et al, 2008, Ning et al, 2011. By altering the lattice defect and subsequent the density of intermediate energy states, it is possible to tune the optical nonlinear response of ferroelectric thin films (Ambika et al, 2011). Metal nanoparticles doped ferroelectrics will introduce additional absorption peak arising from the surface plasmon resonance of nanoparticles.…”