Micro-deformation response of a holographic sensor in highly stretchable polymer hydrogel

作者:Yu, Dan*; Liu, Hongpeng; Wang, Rui; Li, Li; Luo, Suhua; Lv, Jiang; Wang, Weibo
来源:Optics Letters, 2018, 43(13): 3037-3040.
DOI:10.1364/OL.43.003037

摘要

A volume grating-based holographic sensor in highly stretchable PVA/AA polymer for sensing its micro-deformation and, hence, the displacement has been studied. One-dimensional micro-displacement induced by tensile stress is analyzed using a diffraction spectrum in two kinds of sensor construction methods, i.e., transmission and reflection. The dependence of the peak wavelength on the displacement presents a good linear relationship which provides a quantitative sensing strategy for hydrogel micro-deformation. The available sensitivity is better than 4 mu m/0.5 nm (displacement/wavelength shift) using a commercial spectrometer with a resolution of 0.5 nm. Finally, the reversible deformation response further validates the practical applicability of a holographic sensor constructed by photosensitive hydrogel. The optical measurement of micro-displacement as a novel sensing strategy can accelerate the development of the holographic optical element.