论文标题
克服基于挤压的光学传感中的检测损失和噪声
Overcoming detection loss and noise in squeezing-based optical sensing
论文作者
论文摘要
在量子计量学的已知资源中，最实用，最有效的资源是挤压。原子和光的挤压状态改善了相，磁场，极化，机械位移的感应。他们承诺在成像和光谱学中会大大提高信噪比，并且已经用于现实生活中的重力波检测器。但是，尽管比其他州更强大，但它们仍然非常脆弱，这缩小了其应用的范围。特别是，在检测效率低下或噪声较高的测量中，挤压状态无用。在这里，我们在实验上证明了针对损失和噪声的补救措施：检测前强烈无噪声放大。这样，我们实现了用挤压和连贯的光喂养的干涉仪的耐损耗的操作。只有50 \％的检测效率，并且噪声超过50倍以上的挤压光的水平，我们将射击效率限制为6〜dB。子射击相位灵敏度最多生存87％\％损失。将此技术应用于其他类型的光学感测和成像，有望在这些领域充分利用量子资源。
Among the known resources of quantum metrology, one of the most practical and efficient is squeezing. Squeezed states of atoms and light improve the sensing of the phase, magnetic field, polarization, mechanical displacement. They promise to considerably increase signal-to-noise ratio in imaging and spectroscopy, and are already used in real-life gravitational-wave detectors. But despite being more robust than other states, they are still very fragile, which narrows the scope of their application. In particular, squeezed states are useless in measurements where the detection is inefficient or the noise is high. Here, we experimentally demonstrate a remedy against loss and noise: strong noiseless amplification before detection. This way, we achieve loss-tolerant operation of an interferometer fed with squeezed and coherent light. With only 50\% detection efficiency and with noise exceeding the level of squeezed light more than 50 times, we overcome the shot-noise limit by 6~dB. Sub-shot-noise phase sensitivity survives up to 87\% loss. Application of this technique to other types of optical sensing and imaging promises a full use of quantum resources in these fields.
