Magnetic Resonance by Optical Means

我们利用光学手段进行了各种新型的磁共振实验。在Cs和Na原子的基态下，观察到两组光脉冲序列激发产生的同步量子拍回波。这些是用纯光学方法得到的电子自旋回波。D_1跃迁用于激发和检测。Cs实验采用二极管激光器。探测光的法拉第旋转检测信号。测量均匀弛豫时间。利用线偏振光周期性激发，在Cs基态产生m=2相干，并观测到与之相关的自由感应衰减（fid）信号。我们还证明了g因子的符号可以通过使用这些信号来光学地确定。用光学技术测量了苯并和tm^<2+>:SrF_2的短自旋晶格弛豫时间（-10ns）和1:1交叉弛豫时间，这是常规磁共振法无法测量的。研究了Pr^<3+>:LaF_3的光孔燃烧、光子回波、光fid和NMR拉曼外差信号。首次通过实验证实了LaF_3的晶体孪生。发现了光辐照对核磁共振自旋回波信号的增强和核磁共振横向弛豫时间的异常延长。

We performed various new types of magnetic resonance experiment by optical means.Synchronized quantum beat echoes produced by the excitation with two sets of light pulse trains were observed for the ground state of Cs and Na atoms. These are the electron spin echoes obtained by purely optical means. D_1 transitions were used for the excitation and the detection. Diode lasers were used for the Cs experiment. Signals were detected form the Faraday rotation of the probe light. Homogeneous relaxation times were measured.By using periodic excitation with linearly polarized light we generated m=2 coherences in the ground state of Cs and observed free induction decay (fid) signals associated with them. We also demonstrated that the sign of the g-factor can be determined optically by using these signals.Short spin lattice relaxation times (-10ns) and 1:1 cross relaxation times which cannot measured by usual magnetic resonance method were measured by optical techniques in benzil and tm^<2+>:SrF_2. Optical hole burning ,photon echoes ,optical fid and Raman heterodyne signals of NMR were observed for Pr^<3+>:LaF_3. Crystal twinning of LaF_3 was confirmed experimentally for the first time. Enhancement of NMR spin echo signals by optical irradiation and anomalous lengthening of the NMR transverse relaxation times were found.