Sequential parametric amplification: quantum technology with multimode light

参量放大在许多量子技术中起着重要的作用。在经典电子学中，参数放大器和运算放大器一样不可或缺。参量放大器的噪声来自于压缩真空，而压缩真空是量子光学的主力军。通过顺序放置两个参数放大器，就得到了所谓的SU（1,1）干涉仪，这种干涉仪几十年前就在理论上提出，但直到最近才在实验中实现。这是一个有源干涉仪的例子；它优于传统的无源干涉仪，并提供适合许多量子应用的新拓扑。最近的实验证实，顺序参数放大提供了：-相位灵敏度超过短噪声限制；-使用第二个放大器作为光差器件，实现超宽带（高达120THz）光差检测的可能性；在第二放大器增益足够高的情况下，对检测损耗的容忍度。SPARQL将开发多模顺序参数放大，并将其用于当前量子技术的需要。我们将考虑空间/角模式和时间/频率模式的参数放大。因此，我们将在允许损失的情况下实施以下技术：-挤压增强成像和显微镜；-挤压增强拉曼光谱和宽视场显微镜，由于多模结构，速度提高了几个数量级；-压缩增强频率多模量子密钥分配。此外，我们将解决非高斯频率多模量子传感的新领域，以克服压缩增强传感，光谱学和显微镜的限制。

Parametric amplification plays an important role in many quantum technologies. A parametric amplifier is as indispensable as an operational amplifier in classical electronics. The very noise of a parametric amplifier is squeezed vacuum, the workhorse of quantum optics. By placing two parametric amplifiers in sequence one obtains the so-called SU(1,1) interferometer, theoretically proposed decades ago but realized in experiment only recently. This is an example of an active interferometer; it outperforms conventional passive interferometers and provides new topologies suitable for many quantum applications. Confirmed by recent experiments, sequential parametric amplification provides:- phase sensitivity beyond the shot-noise limit; - possibility of ultra-broadband (up to 120THz) optical homodyne detection by using the second amplifier as an optical homodyne device;- tolerance to detection loss provided that the second amplifier gain is sufficiently high.SPARQL will develop multimode sequential parametric amplification and use it for current needs of quantum technology. We will consider parametric amplification of both spatial/angular modes and temporal/frequency modes. As a result, we will implement the following techniques, with tolerance to loss:- squeezing-enhanced imaging and microscopy;- squeezing-enhanced Raman spectroscopy and wide-field microscopy, with orders of magnitude speedup due to the multimode structure;- squeezing-enhanced frequency-multimode quantum key distribution.Moreover, we will address a new area of non-Gaussian frequency-multimode quantum sensing to overcome limits of squeezed-enhanced sensing, spectroscopy and microscopy.