The Large and Tunable Nonlinear Absorption Response of Graphene Oxide Liquid Crystals

In this work, we report on the tuning of the optical transmission properties of the graphene oxide liquid crystal. The proposed tuning method is obtained by irradiating the liquid crystal samples with 532-nm laser irradiation. For this purpose, liquid crystallinity of the graphene oxide is proved by the birefringence measurement method. Large nonlinear absorption has been observed from graphene oxide liquid crystals. Open-aperture Z-scan experiments revealed that the laser irradiation enhanced the nonlinear absorption coefficient by approximately five times in comparison with non-irradiated sample. UV-visible, Raman and Fourier transform infrared spectroscopy clearly demonstrate that graphene oxide liquid crystal is not modified by laser irradiation. This work opened up the method to control and amplify the absorption properties of graphene oxide liquid crystal.