Conventional elastomers doped with benzophenone derivatives as effective media for all-optical fabrication of tunable diffraction elements

Abstract

Simple and effective approach for the fabrication of volume diffraction gratings (VDGs) using different widely used elastic materials is demonstrated for the first time. The method consists in the introduction of UV-photoactive compounds into the ready-to-use elastomeric films with following gratings inscription by a holographic technique. As photoactive dopants a number of methyl-substituted benzophenone derivatives have been tested. Polydimethylsiloxane- and acrylate-based elastic polymers as well as styrene-ethylene-co-butylene-styrene copolymer are exploited as elastomeric matrices. The diffraction gratings of different geometrical parameters are successfully fabricated in all developed elastic materials. The highest value of the refractive index modulation of about 1 × 10⁻³ is achieved. The technique enables to create also slanted gratings and multiple gratings. The use of such gratings as strain-controllable elements for managing of light is demonstrated. Moreover, elastic reflection gratings have been produced for the first time using conventional polydimethylsiloxane (PDMS) material. The proposed approach provides a very flexible, low-cost and effective tool for all-optical fabrication of complex diffraction structures in the broad class of commercially available elastomeric materials that undoubtedly gives a strong impact to the field of soft tunable optics, photonics, and spectroscopy.