Measurement Of Beam Deflection Angle Based On Weak Value Amplification Technology

Quantum weak measurement is widely used in optical precision measurement.Compared with classical measurement,the weak measurement system and the instrument are weakly coupled and will not cause quantum decoherence.The weak measurement can get the amplified weak value after the pre-selection,weak coupling,and post-selection,which can be used for signal amplification and small parameter estimation.This paper is based on the weak value amplification technology to carry out the experimental research on the measurement of the small deflection angle of the beam.First,the Sagnac interferometer was built to generate a small deflection of the beam through the piezoelectric ceramic drive mirror;secondly,the beam angle deflection was converted into the beam lateral position offset,and the detector was used to measure it;finally,the half-wave plate was used to adjust the order.The relative phase? of the clockwise and counterclockwise optical paths maximizes the measurement accuracy of the system.Compared with the traditional measurement method,the weak measurement method can amplify the beam offset and make the measurement result more accurate.The minimum deflection angle of the beam that can be measured by the weak measurement experiment scheme is 3.245 x 10-7 rad,which shows that this method is suitable for the measurement of the small deflection angle of the beam.