损耗与噪声对分束器的量子非破坏性测量的影响

INFLUENCE OF LOSS AND NOISE ON BEAM SPLITTER'S QUANTUM NONDESTRUCTIVE MEASUREMENT

采用量子理论详细地分析有损耗的分束器作为量子非破坏性测量系统时的量子态制备能力和量子光学分流能力与透射损耗和反射损耗的关系.给出当输入探测光的量子起伏为某一确定值时,要实现量子非破坏性测量分束器损耗的上限值.还讨论输人信号光不是相干态而是含有热噪声的相干信号场时,信号光的量子起伏对量子非破坏性测量的影响.

We use quantum theory to analyse the dependence of quantum state preparing ability and quantum optical tapping ability on a beam splitter's transmitting loss and reflecting loss when the losing beam splitter acts as a guantum nondestructive (QND) measurment device. We give out the maximal limit of the beam splitter's loss when the input probe is a nonideal squeezed light and the system can implement QND measurment. We also illustrate how fluctuations and noise of input sin-gal influence the effectiveness of QND measurment.