Nonlinear optical absorption in undoped and cerium-doped BaTiO3 thin films using Z-scan technique

Abstract

BaTiO 3 and BaTiO3:Ce thin films with good surface morphology and tetragonal perovskite structure were fabricated on quartz substrates by pulsed-laser deposition technique at a deposition temperature of 750 °C. The fundamental optical constants (the band gaps, linear refractive indices and absorption coefficients) of the films were obtained through optical transmittance measurements. The nonlinear optical properties of the films were investigated using Z-scan method. The films display large nonlinear absorption effects. The two-photon absorption coefficients of the BaTiO3 and BaTiO3:Ce films were determined to be 51.7 and 59.3 cm/GW, respectively. All the results show that undoped and cerium-doped BaTiO3 ferroelectric thin films have potential applications in absorbing-type optical devices.

Nonlinear optical properties in SrTiO3 thin films by pulsed laser deposition

“…Thus the nonlinear optical absorption in SrTiO 3 thin film stems mainly from TPA. This situation is in consistent with the results in BaTiO 3 film (E g Z3.4 eV) [9,16]. The TPA coefficient b can be obtained by the following equation [17] TðS…”

“…The grain boundary of SrTiO 3 is nonstoichiometric, being 'doped' by the segregated excess Ti and O deficiency [8]. Nonlinear optical properties, such as nonlinear refractive index, two-photon absorption (TPA) were investigated for the ferroelectric films of BaTiO 3 , Ce:BaTiO 3 , PLZT, and PLT [9][10][11]. However, there is no report on nonlinear optic properties in SrTiO 3 dielectric film.…”

Investigation of microstructural and optical properties of (K,Ba)(Ni,Nb)O3−δ thin films fabricated by pulsed laser deposition

“…Various methods, both vacuum-based and non-vacuum based techniques, such as pulse laser deposition (PLD), metalorganic chemical-vapor deposition, sol-gel processing, and streaming process for electrodeless electrochemical deposition (SPEED), have been employed in fabricating epitaxial and polycrystalline films [3][4][5][6]. Among them, one advantage of the vacuum-based techniques is the versatility afforded by the possible use of multiple evaporation/sputtering sources, thereby providing considerable control over the film composition and phase profile.…”

The micro-structural studies of Ni-BaTiO3 nanocomposite films by TEM and EELS

“…For instance, magnetic MNCs (such as Fe, Co, Ni etc.) embedded in BaTiO 3 matrix can greatly enhance the third-order nonlinear susceptibility  (3) compared with the pure dielectric materials [6,7] . A large third-order optical nonlinearity is very useful for optical switching devices so it is critical to fabricate high-quality MNCsBaTiO 3 composite fi lms.…”