Facile solubilization of titanate nanobelts for nonlinear optical investigations.

A homogeneously translucent titanate nanobelt (TNB) suspension was prepared through facile surface modification of pristine TNBs by polymer wrapping with poly(allylamine hydrochloride). The resultant TNB aqueous suspension was found to remain stable for months. The nonlinear optical (NLO) and optical limiting (OL) properties of the TNB suspension were then investigated. We found that the TNB suspension behaves totally differently at 532 and 1064 nm excitation in the nanosecond laser pulse regime. The sample displays remarkable NLO and OL effects at 532 nm, originating from nonlinear scattering. However, the NLO and OL effects are entirely diminished at 1064 nm due to the absence of near-resonant absorption and the subsequent thermal effect.