Precision Measurement Enhancement Based On Noiseless Linear Amplification

Precision measurement physics is a frontier field where physics and metrology,information science,and various disciplines intersect and develop in different directions.It provides new testing methods and new research methods,reveals some new physical phenomena and laws,and promotes the emergence of new precision measurement devices,measurement systems and measurement concepts,and the rapid development of the frontier of the subject.In the actual measurement process,the huge challenge that people face is all kinds of noise that affect the measurement.Using classical means to measure,it can only reach the classical limit or the standard quantum limit accuracy.In order to improve the accuracy and sensitivity of measurement,people turned their attention to the non-classical light field,using the non-classical characteristics of squeezed state,quantum entanglement,etc.,so that the measurement accuracy and sensitivity can surpass the shot noise limit,and in some cases even approach Heisenberg limit^[1].Among them,as a continuous variable quantum state,the squeezed state has a noise characteristic lower than the shot noise limit,and has been used as a good light source to improve the accuracy of quantum measurement since its inception.This novel quantum resource provides an effective means to further improve the precision of precision measurement^[1,2].On the other hand,quantum noiseless linear amplification technology can achieve noiseless linear amplification of signals,improve the signal-to-noise ratio of the measurement,and thereby improve the measurement accuracy.Therefore,combining the advantages of squeezed state-based quantum measurement technology and quantum state noiseless linear amplification technology,and carrying out related quantum measurement research,it is expected to realize a quantum precision measurement enhancement scheme based on noiseless liness amplification and obtain higher precision measurement results.This article focuses on the theory and experiment of squeezed light field and measurement-based noiseless linear amplification（MB-NLA）to achieve precision measurement signal-to-noise ratio enhancement.Its main work includes the following aspects:1.The basic principle of preparing squeezed light is introduced,and 6.00dB squeezed light is prepared by using an optical parametric amplifier.In the phase signal measurement based on the squeezed state,it breaks through the shot noise of 2.40dB,which is 1.36 times higher than the signal-to- noise ratio of the coherent optical measurement.2.Combining the advantages of squeezed state-based quantum measurement technology and quantum state noiseless linear amplification technology,a quantum precision measurement enhancement scheme based on noiseless linear amplification is realized.This solution further increases the signal- to-noise ratio by 1.83 times on the basis of the squeezed light measurement solution.Compared with the classic measurement,the overall signal-to- noise ratio is increased by 2.50 times.