Spatial Squeezing, Entanglement, and Solitonic EPR Sources in Chi(2) Minicavities

该奖项旨在支持光学二次谐波产生中的空间压缩研究。显示时域正交压缩、双光束相关和其他量子光学现象的实用辐射场源在20世纪80年代和90年代得到发展。我们将研究由光学二次谐波产生的非经典光的空间方面。空间压缩已经在理论上预测出现在二次谐波产生作为横向调制不稳定的亚临界前兆。我们正在进行一系列实验，旨在观察调制不稳定阈值以上的经典模式，以及阈值以下的量子特征。实验工作采用连续波和纳秒脉冲近红外光源驱动的单谐振和双谐振光腔。详细的测量将压缩的程度作为一个函数的腔调谐，相位失配，和空间波数。我们还将研究光学腔内部产生的二次谐波场直接驱动光学参量振荡竞争过程的参数机制。这种所谓的内泵浦参量振荡器（IPOPO）具有独特的特点，即显示非经典相关性的下转换参量场是使用单个非线性晶体在与入射泵浦光束相同的波长上产生的。这样就不需要单独的倍频级，从而降低了器件的复杂性，并极大地促进了组合过程的频率调谐。由此产生的正交压缩场将用于测量空间位移与亚弹噪声分辨率。在进行实验工作的同时，我们将对不同可能的空腔结构的空间压缩谱进行理论计算。特别地，我们将对在IPOPO器件中提供空间调制场的连续可变纠缠的参数体系进行研究。该项目的教育部分将包括培训研究生掌握现代实验和理论技术，使非经典光场的应用成为可能。

This award is in support of studies of spatial squeezing in optical second harmonic generation. Practical sources of radiation fields exhibiting time domain quadrature squeezing, twin-beam correlations, and other quantum optical phenomena were developed in the 1980's and 1990's. We will investigate spatial aspects of non-classical light generated by optical second harmonic generation. Spatial squeezing has been theoretically predicted to appear in second harmonic generation as a sub-critical precursor of transverse modulational instability. We are working on a series of experiments aimed at observing both classical patterns above the modulational instability threshold, as well as the below threshold quantum signatures. The experimental work uses singly and doubly resonant optical cavities driven by continuous wave and nanosecond pulsed near infrared sources. Detailed measurements will be made of the degree of squeezing as a function of cavity tuning, phase mismatch, and spatial wavenumber. We will also work with parameter regimes where the second harmonic field that is internally generated in the optical cavity directly drives the competing process of optical parametric oscillation. This so-called internally pumped optical parametric oscillator (IPOPO) has the unique feature that the down converted parametric fields that display non-classical correlations are generated at the same wavelength as the incident pump beam using a single nonlinear crystal. This eliminates the need for separate frequency doubling stages, which reduces device complexity, and greatly facilitates frequency tuning of the combined process. The resulting quadrature squeezed fields will be used for measurements of spatial displacement with sub shot-noise resolution.In parallel with the experimental work we will perform theoretical calculations of the spectrum of spatial squeezing for the different possible cavity configurations. In particular a search will be made for parameter regimes that provide continuous variable entanglement of spatially modulated fields in the IPOPO device. The educational component of the project will include training graduate students in modern experimental and theoretical techniques that enable applications of non-classical light fields.