公开(公告)号：US06806784B2

公开(公告)日：2004-10-19

申请号：US10175498

申请日：2002-06-20

申请人： Leo Hollberg ,  John Kitching

发明人： Leo Hollberg ,  John Kitching

IPC分类号： H03B1700

CPC分类号： H03L7/26 ,  G04F5/14 ,  G04F5/145 ,  H01S3/1304 ,  H01S3/305 ,  H01S5/0687 ,  H01S5/183

摘要： A microwave frequency standard is provided which allows for miniaturization down to length scales of order one micron, comprising a modulated light field originating from a laser that illuminates a collection of quantum absorbers contained in a micro-machined cell. The frequency standard of the present invention can be based on all-optical excitation techniques such as coherent population trapping (CPT) and stimulated Raman scattering or on conventional microwave-excited designs. In a CPT-based embodiment, a photodetector detects a change in transmitted power through the cell and that is used to stabilize an external oscillator to correspond to the absorber's transition frequency by locking the laser modulation frequency to the transition frequency. In a stimulated Raman scattering (SRS) embodiment, a high-speed photodetector detects a laser field transmitted through the cell beating with a second field originating in the cell. Both the locked laser modulation frequency and the beat frequency are very stable as they are referenced directly to the atomic transition.

摘要翻译： 提供了一种微波频率标准，其允许小型化至1微米级的长度尺度，包括源自激光器的调制光场，其照射微加工单元中所包含的量子吸收体的集合。 本发明的频率标准可以基于全光激发技术，例如相干群体捕获（CPT）和受激拉曼散射或在常规微波激发设计上。 在基于CPT的实施例中，光电检测器通过将激光调制频率锁定到转换频率来检测通过单元的发射功率的变化，并且其用于使外部振荡器稳定以对应于吸收器的转换频率。 在受激喇曼散射（SRS）实施例中，高速光电探测器检测通过电池传输的激光场与源自电池的第二场相撞。 锁定的激光调制频率和拍频都是非常稳定的，因为它们直接参照原子跃迁。