Holographic Sensing Response Of High Elastic Polymer Micro Deformation

Optical sensing has been widely concerned because of its long-distance,non-contact and visual characteristics.However,due to the complex fabrication,high cost and brittleness of the substrate,the application of PCSS is limited.By recording the diffraction spectrum of the holographic grating inside the photosensitive material,the holographic sensor can obtain the sensing performance of narrow diffraction spectrum and high linearity,which has an important application value for characterizing the deformation of the object.The research work is mainly carried out from four aspects:(1)A new type of photosensitive acrylamide high elastic polymer is developed as the recording medium of holographic sensor,providing suitable polymer gel material for the development of holographic deformation sensor.Two kinds of holographic sensing devices,transmission type and reflection type,are constructed to test and analyze the sensing response performance of the sensor under tension and compression deformation.(2)The relationship between the peak wavelength of diffraction spectrum of transmission grating and reflection grating and deformation displacement is analyzed.The absorption spectrum of the grating is analyzed to explore the cause of red shift of the transmission grating,and the average refractive index of the material is analyzed to explore the cause of blue shift of the reflection grating in the process of stretching.The reversibility and repeatability of tensile deformation study are characterized by the diffraction spectra of two kinds of volume gratings.The tensile properties of materials with different thickness were explored.(3)The linear relationship between the peak wavelength of reflection grating and the pressure is analyzed.Through theoretical description and comparison of sensing parameters,the response mechanism of reflection grating in micro deformation sensing is revealed,and the potential application of polymer holographic deformation sensor is explored.The response,reversibility and repeatability of deformation sensing of reflection grating during compression are studied.(4)By compressing the volume gratings recorded at different angles,the spectral response can basically return to the original position after compression.The sensing relationship between the peak wavelength of transmission grating and the pressure under compression deformation is explored.The response,reversibility and repeatability of the transmission grating deformation sensing in the compression process are studied.