Pure optical nano-writing on light-switchable spiropyrans/merocyanine thin film

We report optical writing at the nanometer scale of spin coated PMMA-spiropyran films. By using a near-field optical microscope, pure optical nano-writing with a resolution of 160 nm and writing speed of 0.4?m/s was achieved. Simultaneous topographic and optical writing was also obtained by simply coupling to the near-field few more mW of laser power. Due to the fast optical response of the spiropyran molecule, nanolithography on PMMA-spyropyran thin films appears to be very attractive for future photonics applications. © 2014 Optical Society of America.