Manipulation of population transfer by stimulated emission process

已经开发了两种技术用于控制NO里德堡态中的级联型放大自发辐射途径。第一种方法，称为开关，是基于破坏的人口反转所需的放大。第二种方法，称为播种，利用外部场的注入。种子池中产生的弱ASE辐射与泵浦光共线传播，作为主池中倒置介质的种子光。通过利用光学滤波提取期望的种子波长，实现了对所选择的电子跃迁的放大。此外，选择性增强属于同一个里德伯系统之间的转动跃迁是通过利用它们不同的偏振特性。最后，我们证明了开关和种子的联合使用提供了转动选择性，并研究了外注入辐射对双光子激光诱导放大自发辐射（LI-ASE）的影响。在种子单元中通过相同的LI-ASE过程产生的波充当在主单元中创建的反转介质的种子场。在CO分子的B1 Z +→ A1 II（0，3）跃迁中获得了近10倍的增益。我们证明了B_1Z ~+→ A_1II（0，4）带的单转动跃迁被激光辐射的注入选择性地放大。这种泵浦和种子布置通过简单地调谐种子激光器频率来促进分子光谱的检测。

Two techniques have been developed for control of cascade-type amplified spontaneous emission pathways in the NO Rydberg states. The first method, referred to as switching, is based on destruction of the population inversion required for amplification. The second method, called seeding, utilizes the injection of external field. The weak ASE radiation generated in a seeder cell travels collinearly with pump beams, acting as seeder light for the inverted medium in a main cell. By extracting desired seeder wavelengths with optical filtering, amplification of the selected electronic transition is realized. In addition, selective enhancement between the rotational transitions belonging to the same inter-Rydberg system is achieved by taking advantage of their different polarization properties. Finally, we demonstrated that the combined use of switching and seeding provided with rotational selectivity.The effect of externally injected radiation on the two-photon laser induced amplified spontaneous emission (LI-ASE) has been investigated. The wave generated via the same LI-ASE process in a seeder cell acts as a seeder field for the inverted medium created in a main cell. A nearly tenfold gain is achieved in the B1Z+→A1II(0, 3) transition of the CO molecule. We demonstrate that the single rotational transition in the B1Z+→A1II(0, 4) band is selectively amplified by injection of laser radiation. This pump and seed arrangement facilitates detection of molecular spectra by simply tuning the seed laser frequency.