The recording method of planar holographic grating with variable diffraction efficiency by phase modulations

We propose a simple method to record the holographic grating for achieving different diffraction efficiencies in different exposure zones. Two phases are employed to form the desired periodic fringes with controllable diffraction efficiency according to the analytical formula based on interference. Numerical simulations are performed to demonstrate the method, and various experimental noises are analyzed. The result shows that the method can achieve the fabrication of the grating with variable diffraction efficiency successfully. This is a simple and efficient method for recording various gratings with different modulated intensities in large areas.