Pressure response characterization in novel PQ doped poly(MMA-co-LMA) elastic photopolymer

•A novel elastic photopolymer based holographic pressure sensor is developed.•The improvement of spectrum response performance in sensing pressure is confirmed.•Line pressure response sensitivity provide a significant foundation for the practical application. A holographic pressure sensor based on phenanthraquinone (PQ) doped poly(methyl methacrylate-co-lauryl methacrylate) (poly(MMA-co-LMA)) elastic photopolymer is developed by a thermal polymerization. A slanted reflection grating recorded in the photopolymer is used to construct the holographic pressure sensor. The spectrum response performance of the holographic pressure sensor is characterized in the samples with the various thicknesses and MMA component proportions. The maximum of the peak wavelength shifts reaches up to 146.5 nm. The linear pressure force response range is 0–7.51 N (pressure 0–7.51 × 104 Pa) and the linear sensitivity is 0.052 N/nm (5.2 × 104 Pa/nm). Compared with the typical acrylamide based holographic sensor (maximum of the peak wavelength shifts 25 nm at 1.58 × 104 Pa pressure), the novel holographic sensor provides a larger linear measurable range and higher sensitivity in response to the changes in pressures. The quantitative sensing precision confirms the performance improvement of the holographic pressure sensor. To reveal the pressure sensing mechanism, the average refractive index of the polymer was measured using a standard Michelson interferometer. Under a longitudinal pressure deformation, the common reductions of average refractive index and fringe space of grating are the primary inducement for the pressure response. The holographic pressure sensor based on poly(MMA-co-LMA) can accelerate the practical application of holographic optical elements.