QUANTUM-MECHANICAL NOISE IN AN INTERFEROMETER
QUANTUM-MECHANICAL NOISE IN AN INTERFEROMETER
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DOI：
10.1103/physrevd.23.1693
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发表时间：
1981-01-01
影响因子：
5
通讯作者：
CAVES, CM
中科院分区：
文献类型：
--
作者：
CAVES, CM
目前正在开发的用来探测引力波的干涉仪，是通过测量相距甚远的质量的相对位置来工作的。量子力学噪声的两个基本来源决定了这种干涉仪的灵敏度：（i）输出光子数量的波动（光子计数误差）和（ii）质量上辐射压力的波动（辐射压力误差）。由于可用的连续波激光器的低功率，目前计划的干涉仪的灵敏度将受到光子计数误差的限制。本文分析了这两种量子噪声，提出了一种新的量子噪声测量技术--”压缩态”技术，它可以减小光子计数误差，同时增大辐射压力误差，反之亦然。压缩态技术的关键要求是进入干涉仪通常未使用的输入端口的光的状态必须不是真空，如在标准干涉仪中，而是“压缩态”-一种在两个正交相位中不确定性不相等的状态。压缩态可以通过各种非线性光学过程产生，包括简并参量放大。
The interferometers now being developed to detect gravitational waves work by measuring the relative positions of widely separated masses. Two fundamental sources of quantum-mechanical noise determine the sensitivity of such an interferometer:(i) fluctuations in number of output photons (photon-counting error) and (ii) fluctuations in radiation pressure on the masses (radiation-pressure error). Because of the low power of available continuous-wave lasers, the sensitivity of currently planned interferometers will be limited by photon-counting error. This paper presents an analysis of the two types of quantum-mechanical noise, and it proposes a new technique—the" squeezed-state" technique—that allows one to decrease the photon-counting error while increasing the radiation-pressure error, or vice versa. The key requirement of the squeezed-state technique is that the state of the light entering the interferometer's normally unused input port must be not the vacuum, as in a standard interferometer, but rather a" squeezed state"—a state whose uncertainties in the two quadrature phases are unequal. Squeezed states can be generated by a variety of nonlinear optical processes, including degenerate parametric amplification.