自发

The studies on SPDC havereceived a great deal of attention.

因此，自发参量下转换过程的研究就成为学术界的焦点问题。

In this thesis, an efficient scheme of generating single photon with SPDC is presented, and the important application in quantum key distribution is also introduced.

本文主要提出了一种利用自发参量下转换获得高效单光子源的方案，介绍了高效单光子源在量子密钥分配的重要应用，并提出基于这种单光子源实现受控非门的理论方案。

Many experiments have been reported for momentum and frequency entangledstate with type I SPDC pumped by coninuous-wavelaser and are supported intheoretical analysis well.

在连续激光泵浦的I型自发参量下转换过程中，对空间、频率纠缠的双光子的实验研究工作已有不少报导，且在理论上也得到很好的解释。

A theoretical scheme of generating high efficiency single photon using multi-dots delay detection in the process of SPDC is presented, by which the enhancement of the efficiency of controlled not gate is also studied.

二、提出了一种利用自发参量下转换过程采用多点延时探测触发的方法获得高效单光子源的方案，并基于它提高了实现受控非门的效率。

The generating origin of the light field with SPDC expounded with the interaction of the pumping photons with the nonlinear crystals.

分析了单色泵浦光子流和量子真空噪声对非线性晶体的综合作用，从泵浦光与非线性晶体的相互作用过程解释了自发参量下转换光场的产生根源，推导了SPDC双光子态的数学表达式，并给出其几率解释

The creative works are as follows: 1. We show a scheme to generate high efficiency single photon via multi-dots delay detection with SPDC.

在这些研究工作中，属创新性工作的有两点： 1、提出了一种利用自发参量下转换过程采用多点延时探测触发获得高效单光子源的方法，可以利用它来实现基于单光子的量子密钥分配方案和量子计算中的量子逻辑门。

Sure, there's still room for spontaneity.

当然，还是有自发的余地。

"The essence of pleasure is spontaneity."

快乐的本质是自发。

In this thesis, spontaneous emission from three-level atom in Photonic Crystal has been investigated.

本论文研究的主要内容为处于光子晶体内的三能级原子的自发辐射荧光行为。

In addition, we also observed modified spontaneous emission pattern.

另外，我们也观察到了被修正过的自发辐射的场形。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。