Wolfgramm F, Xing X, Cerè A, Predojević A, Steinberg A M, Mitchell M W
Institut de Ciencies Fotoniques, Mediterranean Technology Park, Castelldefels, Barcelona, Spain.
Opt Express. 2008 Oct 27;16(22):18145-51. doi: 10.1364/oe.16.018145.
We demonstrate a high-brightness source of pairs of indistinguishable photons based on a type-II phase-matched doubly-resonant optical parametric oscillator operated far below threshold. The cavityenhanced down-conversion output of a PPKTP crystal is coupled into two single-mode fibers with a mode coupling efficiency of 58%. The high degree of indistinguishability between the photons of a pair is demonstrated by a Hong-Ou-Mandel interference visibility of higher than 90% without any filtering at an instantaneous coincidence rate of 450,000 pairs/s per mW of pump power per nm of down-conversion bandwidth. For the degenerate spectral mode with a linewidth of 7 MHz at 795 nm a rate of 70 pairs/(s mW MHz) is estimated, increasing the spectral brightness for indistinguishable photons by two orders of magnitude compared to similar previous sources.
我们展示了一种基于II型相位匹配双共振光学参量振荡器的高亮度不可区分光子对源，该振荡器在远低于阈值的条件下运行。PPKTP晶体的腔增强下转换输出被耦合到两根单模光纤中，模式耦合效率为58%。在每纳米下转换带宽每毫瓦泵浦功率的瞬时符合率为450,000对/秒的情况下，一对光子之间的高度不可区分性通过高于90%的Hong-Ou-Mandel干涉可见度得到证明，且无需任何滤波。对于在795纳米处线宽为7兆赫兹的简并光谱模式，估计速率为70对/(秒·毫瓦·兆赫兹)，与之前类似的光源相比，不可区分光子的光谱亮度提高了两个数量级。
