Temperature effects on axial dispersion in a photopolymer-based holographic lens

This study aims to discover whether temperature has an effect on axial dispersion in a photopolymer-based holographic lens. A typical coaxial holographic lens is recorded in the acrylamide polymer system. The axial dispersion spectrum is read and collected by using a supercontinuum source and spectrometer. The temperature effects on axial dispersion in a photopolymer-based holographic lens are investigated experimentally. With increasing temperature from 23°C to 70°C, the diffraction spectrum shifts, and the axial dispersion is shortened evidently. The peak wavelength of the dispersion spectrum shifts from 629.05 to 612.50 nm with an obvious blueshift of 16.55 nm. The spatial position of the peak wavelength also decreases from around 40 to 22 mm from the material surface. Simultaneously, the position sensitivity of the device reduces from 2.53 to 1.50 nm/mm. The shortening of the effective focal length and reduction of the diffraction intensity indicate that the high temperature above 40°C is a disadvantageous factor for actual use of a holographic lens-based spectral confocal measuring device. In practical application, a constant temperature is a significant means to ensure the measurement accuracy and range.