Study of Large Purcell Effect in Three-dimensional microcavities

三维微腔大珀塞尔效应研究

基本信息

批准号：
14350154
负责人：
SUEMUNE Ikuo
金额：
$ 9.22万
依托单位：
HOKKAIDO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

项目摘要

With the extension of the internet and related communication technologies, the security issue is getting more and more important these days. The most secure communication will be the quantum cryptography which carries informations with individual photons separately. Photons are fundamental quantums and it is not possible to get the information without disturbing the photon conditions. For this purpose, single photon and not more than two photons should be generated in every pulse. This is not possible with conventional semiconductor lasers since the photon number is Poisson-distributed. The solution for this problem is the construction of 3-dimensional microcavities and insertion of single quantum dot of which quantum state is strongly coupled with the cavity mode. This will emit photons one by one.Toward this direction, pyramidal three-dimensional microcavities were proposed to realize the single photon source. The resonance modes were analyzed numerically with finite-difference time-domain method and the resonance Q values were theoretically investigated to increase the values. The Q value of 〜5000 was experimentally observed and the enhanced spontaneous emission was observed at the wavelength of the resonance mode by inserting CdS quantum dots inside the pyramid. The peak wavelength was very stable against the temperature change and the emission peak was Just at the absorption peak observed in reflection spectrum measurements. These results show the Purcell effect although the observations were done with indirect method. More direct time-resolved measurements are being prepared by increasing the sensitivity of a streak camera and the direct measurements are now under study.

随着互联网和相关通信技术的扩展，当今的安全问题越来越重要。最安全的通信将是量子密码学，该密码分别带有各个照片。光子是基本的量子，不可能在不打扰光子条件的情况下获取信息。为此，每个脉冲都应生成单个光子，而不超过两张照片。传统的半导体激光器是不可能的，因为光子编号是泊松数分布的。解决此问题的解决方案是构建3维微腔和插入单量子点的插入，其量子态与腔模式强烈耦合。这将一一散发照片。提出了这个方向，提议锥体三维微腔来实现单个光子源。通过有限差分时间域法对共振模式进行单独分析，并理论上研究了共振Q值以增加值。实验观察到了〜5000的Q值，并通过将CDS量子点插入金字塔中的CDS量子点在共振模式的波长下观察到增强的赞助商发射。峰值波长在温度变化方面非常稳定，并且在反射光谱测量中观察到的吸收峰处的发射峰值。这些结果表明了percell效应，尽管观察结果是用间接方法完成的。通过提高条纹摄像头的灵敏度，正在进行直接测量，正在进行更直接的时间分辨测量。