A tunable random laser based on lotus leaf

Abstract

A tunable random laser with a bendable poly (dimethylsiloxane) (PDMS) substrate was described. The substrate is prepared based on soft lithography from lotus leaf, which have the similar surface structure with lotus leaf such as micropapilla. The micro-papilla on the surface of the substrate will provide efficient multiple scattering for the photon generated from gain medium, and the coherent random lasing is emerging because photon form closed-loop path among micropapilla via the scattering. The wavelength of the random laser emission spectrum can be tuned as wide as 26.0 nm by changing the pump position due to the diverse distribution of the micro-scale features on the soft substrate. The random laser provides a promising solution toward the realization of many laser based applications such as integrating optical biosensors on chips, probing micro-scale structural alterations and developing a multi-color even white random laser.