Reiten M T, Grischkowsky D, Cheville R A
School of Electrical and Computer Engineering and Center for Laser and Photonics Research, Oklahoma State University, Stillwater, Oklahoma 74078, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2001 Sep;64(3 Pt 2):036604. doi: 10.1103/PhysRevE.64.036604. Epub 2001 Aug 27.
We report time-domain measurements with subpicosecond resolution of optical tunneling of terahertz electromagnetic pulses undergoing frustrated total internal reflection. Measurements of the transmitted electromagnetic pulses over a 3 THz bandwidth permits direct determination of frequency-dependent phase and amplitude changes in both the thin and opaque barrier limits in a single measurement. A complex frequency response function describing propagation through the barrier is developed based upon linear dispersion theory and the Fresnel coefficients at complex angles in the optical barrier. Our measurements are in excellent agreement with this theoretical model across the experimentally determined bandwidth; the model makes no assumptions about the beam path through the barrier and has no adjustable parameters. The theory is shown to satisfy the Kramers-Kronig relations, indicating causal propagation across the barrier.
我们报告了对经历受抑全内反射的太赫兹电磁脉冲的光学隧穿进行亚皮秒分辨率的时域测量。在3太赫兹带宽上对传输的电磁脉冲进行测量，可以在一次测量中直接确定薄势垒极限和不透明势垒极限中频率相关的相位和幅度变化。基于线性色散理论以及光学势垒中复角度下的菲涅耳系数，建立了一个描述通过势垒传播的复频率响应函数。我们的测量结果在实验确定的带宽范围内与该理论模型高度吻合；该模型对穿过势垒的光束路径不做任何假设，也没有可调参数。结果表明该理论满足克拉默斯－克勒尼希关系，表明在势垒上的因果传播。
