| 查看: 320 | 回复: 2 | |||
| 当前主题已经存档。 | |||
| 【有奖交流】积极回复本帖子，参与交流，就有机会分得作者 XXQ_carol 的 10 个金币 | |||
[交流]
【求助】参量下转化是怎么回事儿？
|
|||
|
光在一些晶体中出现参量下转化这种非线性现象，产生纠缠光子对。这个参量下转化到底是怎么回事儿？好像还分了Ⅰ型和Ⅱ型的，这两者有什么区别？ 有没有前辈高人可以指点一下啊！先谢了啊！ [ Last edited by lvzhu2007 on 2008-9-22 at 14:11 ] |
回复此楼» 猜你喜欢
孩子确诊有中度注意力缺陷
已经有12人回复
-
2025冷门绝学什么时候出结果
已经有3人回复
-
天津工业大学郑柳春团队欢迎化学化工、高分子化学或有机合成方向的博士生和硕士生加入
已经有4人回复
-
康复大学泰山学者周祺惠团队招收博士研究生
已经有6人回复
-
AI论文写作工具：是科研加速器还是学术作弊器？
已经有3人回复
-
2026博士申请-功能高分子，水凝胶方向
已经有6人回复
-
论文投稿，期刊推荐
已经有4人回复
-
硕士和导师闹得不愉快
已经有13人回复
-
请问2026国家基金面上项目会启动申2停1吗
已经有5人回复
-
同一篇文章，用不同账号投稿对编辑决定是否送审有没有影响？
已经有3人回复
gaoky2008
木虫 (著名写手)
- 应助: 0 (幼儿园)
- 金币: 6745.6
- 帖子: 1563
- 在线: 139.7小时
- 虫号: 472596
- 注册: 2007-12-04
- 性别: GG
- 专业: 高分子合成化学
|
Wikipedia的解释： Spontaneous parametric down-conversion (SPDC) is an important process in quantum optics. A nonlinear crystal splits incoming photons into pairs of photons of lower energy whose combined energy and momentum are equal to the energy and momentum of the original photon. The state of the crystal is left unchanged in the process, which is why energy and momentum must be conserved (this is related to phase matching in nonlinear optics). This phase matching dictates that the photon pair be entangled in the frequency domain. SPDC is stimulated by random vacuum fluctuations, as such the photon pairs are created at random times. However, if one of the pair (the "signal"  is detected at any time then we know its partner (the "idler" is present. Either signal and idler photons share the same polarisation (type I) or they have perpendicular polarisations (type II). The output of a type I down converter is a squeezed vacuum, which contains only even photon number terms. The output of the type II down converter is a two-mode squeezed vacuum.SPDC allows for the creation of optical fields containing (to a good approximation) a single photon. As of 2005, this is the predominant mechanism for experimentalists to create single photons (also known as Fock states)[1]. The single photons as well as the photon pairs are often used in quantum information experiments and applications like quantum cryptography and the Bell test experiments. 原文地址： http://en.wikipedia.org/wiki/Spo ... ric_down_conversion |
2楼2008-09-22 21:52:40
3楼2008-09-22 22:16:23