Beam deflection as an important beam control technique is widely used in laser radar,space laser communication,optical switch,high energy laser system,etc. Especially,a beam scanning system combining liquid crystal optical phased array with volume Bragg gratings can achieve large angle beam deflection,and has unique advantages in application of multi-beam deflection,such as miniaturization,light weight,simple structure,quick response and so on.Volume Bragg grating is a holographic element based on PTR glass,which deflects the incident light in the Prague angle range and directly transmits the incident light at other angles.Multiplexed volume Bragg gratings have several grating channels written in a piece of PTR glass.By use of the angular selectivity of multi-channel volume Bragg grating,the angle interval between the incident and exit angles are designed to provide the different angular magnification.