【作者】 王强；

【导师】 袁春华；

【作者基本信息】 华东师范大学 ， 光学， 2021， 硕士

【摘要】 马赫-曾德尔干涉仪与SU(1.1)干涉仪,是当前精密测量领域中主流研究的两类干涉仪,两者均存在一定的优缺点。马赫-曾德尔干涉仪在采用经典光源(相干光)时相位灵敏度无法突破标准量子极限(Standard quantum limit,SQL):(?),其中代表干涉仪中的光子数。SU(1.1)干涉仪虽然相位灵敏度可以突破SQL,但受限于仪器条件无法容纳较大的光子数,导致绝对相位灵敏度不高。为此结合这两类干涉仪,一类新型多通道干涉仪被提出。本文主要研究了多通道干涉仪中的相位估值极限以及在有损耗的情形下,强度探测以及零拍探测两类探测方式的相位灵敏度。首先利用量子费歇尔信息以及量子费歇尔信息矩阵研究了多通道干涉仪在特定输入的情况下的相位估值极限。结果显示在输入单光场的情况下,相位平均后的量子费歇尔信息与量子费歇尔信息矩阵得到的相位估值边界——量子克拉美罗界(quantum Cram(?)r-Rao bound,QCRB)相同,该边界不受限于输入态的量子性,只与输入光强有关。然后我们进一步研究了输入双相干态的情况,发现可以通过调整透射系数来消除相干光携带的初始相位对量子克拉美罗界的影响。其次利用误差传播理论研究了多通道干涉仪中强度探测以及零拍探测这两种不同探测方法的相位灵敏度。研究结果得到在无损情形下这两种探测方法均可以击败标准量子极限逼近量子克拉美罗界。然而当考虑光子数损耗后,零拍探测的精度强于强度探测的精度。而且对零拍探测可以通过调节多通道干涉仪的耦合参数进一步增强其抗损耗能力。更多还原

【Abstract】 Mach-Zehnder interferometer(MZI)and SU(1,1)(SUI)interferometer are the mainstream interferometers in the field of current research,but both of them have some defects.In a generic interferometric measurement using an MZI and classical light sources the precision of estimating the relative phase delay inside the interferometer is bounded by standard quantum limit(SQL):(?),where is the average photon number inside interferometer.SU(1,1)interferometer cannot tolerate large photon numbers,resulting in poor absolute phase accuracy.For this reason,a new type of multi-channel interferometer is proposed by combining MZI and SUI.In this paper,the phase estimation limit of multichannel interferometers and the phase sensitivity of intensity detection and homodyne detection under the condition of loss are studied.Firstly,we use quantum Fisher information and quantum Fisher information matrix to study the phase estimation limit of multichannel interferometer in the case of specific input.The results show that in the case of single MZI input,quantum Cram(?)r-Rao bound(QCRB)of the quantum Fisher information after phase averaging is the same as the QCRB obtained by the quantum Fisher information matrix.This bound is not limited by the quantum properties of the input states,but only depends on the input light intensity.Then we further investigate the case of the input double coherent states.It is found that we can eliminate the influence of the initial phase carried by coherent light on the QCRB by adjusting the transmission coefficient.Secondly,the phase sensitivity of intensity detection and homodyne detection in multichannel interferometer is studied by using error propagation theory.The results show that the two detection methods can beat the SQL approximation QCRB in lossless condition.When the photon number loss is considered,the accuracy of homodyne detection is better than that of intensity detection.Moreover,the antiloss ability of the multichannel interferometer can be further enhanced by adjusting the coupling parameters of the homodyne detector.更多还原