Application of Optical Kerr Gate with SrTiO ₃ Crystal in Acquisition of Gated Spectra from a Supercontinuum

Abstract

We investigate the optical Kerr effect of SrTiO3 (STO) crystal, of which the nonlinear response time was measured to be less than 200 fs, while the nonlinear refractive index is estimated to be 2.16 × 10 −15 cm 2 /W. Using the optical Kerr gate (OKG) technique with an STO crystal as the Kerr medium, we obtain narrow-bandwidth and symmetric gated spectra from a supercontinuum generated in distilled water by a femtosecond laser. The experimental results show superiority compared with the gated spectra obtained using OKG with CS2 as the Kerr medium, demonstrating that STO crystal is a promising OKG medium.

High contrast ballistic imaging using a femtosecond optical Kerr gate of SrTiO3 crystal

“…SrTiO 3 crystal (STO) is a promising transparent material and has a good lattice match to most materials with the perovskite structure, and has been widely used in special optical windows and high quality sputtering targets [17,18]. The nonlinear response of STO originates from electronic processes, and the nonlinear refractive index is estimated to be 2.16 × 10 −15 cm 2 W −1 [19]. As the STO crystal has good nonlinear optical properties, it may be attractive in the application of the OKG technique in the future.…”