METHOD AND APPARATUS FOR MEASURING DIFFRACTION EFFICIENCY OF HOLOGRAM

摘要

PURPOSE:To measure diffraction efficiency over the whole hologram by obtaining diffraction efficiency on the basis of the intensity of permeable light, intensity of light incident on the hologram, intensity of light incident on a specified position and intensity of noise light. CONSTITUTION:A laser beam having a preset wave length is irradiated to the whole hologram having interference fringes recorded thereon to measure the intensity I0 of light permeating straight through the hologram, intensity I1 of the laser beam incident on the hologram, intensity IiA of the laser beam incident on a specified position of the hologram and intensity InA of noise light on the specified position of the hologram. The diffraction efficiency eta of the hologram is obtained on the basis of these four intensity according the following formula: eta = (1 - I0/Ii - I - InA/IiA) X 100%.