A PDMS-Polymer Based Flexible DOE for Tunable Beam Shaping

This paper presents a PDMS-polymer based flexible diffractive optical element (DOE) for tunable beam shaping, which combine the mechanical adaptability of PDMS with the precise micro-structure formation enabled by polymer patterning. A PDMS-polymer based flexible tunable DOE is described and designed. And a detailed fabrication technology is provided for the designed DOE. The experimental results show that the fabricated flexible DOE can shape a Gaussian beam to rectangular beam. The shaped rectangular beam can be tuned by applying mechanical strain, which can introduce 0∼-32.21% length and 0∼+12.31% width variation by applying 0∼70% mechanical strain in horizontal direction, and 0∼+22.81% length and 0∼-30.97% width variation by applying 0∼70% mechanical strain in longitudinal direction. The changes in CV and diffractive efficiency of the shaped beam during this process are within an acceptable range of less than 12%. Fatigue resistance test also demonstrated that the proposed flexible DOE exhibited stable tunable performance during 500 times strain-restore, indicating excellent durability with the CV change less than 6% and diffractive efficiency change less than 2%. This approach provides a cost-effective and practical solution for dynamic beam shaping applications.