All optical sub diffraction multilevel data encoding onto azo polymeric thin films

TL;DR

This paper demonstrates a novel all-optical method for multilevel data encoding onto azo-polymer thin films using photo-induced birefringence, enabling polarization-encoded information storage and retrieval at sub-diffraction scales.

Contribution

It introduces a new technique for multilevel data encoding in azo-polymer films via photo-induced birefringence, combining writing and reading with near-field optical microscopy.

Findings

Successful creation of 5-level bits through birefringence control

Effective polarization modulation for data retrieval

Potential for high-density optical data storage

Abstract

By exploiting photo-induced reorientation in azo-polymer thin films, we demonstrate all-optical polarization-encoded information storage with a scanning near-field optical microscope. In the writing routine, 5-level bits are created by associating different bit values to different birefringence directions, induced in the polymer after illumination with linearly polarized light. The reading routine is then performed by implementing polarization-modulation techniques on the same near-field microscope, in order to measure the encoded birefringence direction.