论文标题
样品厚度测量通过相敏的Terahertz Upconversion检测
Sample thickness measurements by phase-sensitive terahertz upconversion detection
论文作者
论文摘要
非线性频率转换提供了一种优雅的方法，可以在光谱范围内检测光子与泵波长不同，从而使其对具有固有低能的光子具有很高的吸引力。除了以光子数为代表的光的强度之外，它们的相位还提供了重要的信息并实现了大量应用。我们通过仅检测可见光来提出一种在Terahertz光谱范围内的相敏度测量方法。使用所涉及的超短脉冲的频率转换光子和剩余的泵光子的光学干扰，证明了层厚度的快速测定。该新方法可以使用标准SCMOS设备对Terahertz脉冲进行相位分辨的检测，同时达到小于一秒钟的样品测量时间，精确误差小于0.6％。
Nonlinear frequency conversion provides an elegant method to detect photons in a spectral range which differs from the pump wavelength, making it highly attractive for photons with inherently low energy. Aside from the intensity of the light, represented by the number of photons, their phase provides important information and enables a plethora of applications. We present a phase-sensitive measurement method in the terahertz spectral range by only detecting visible light. Using the optical interference of frequency-converted photons and leftover pump photons of the involved ultrashort pulses, fast determination of layer-thicknesses is demonstrated. The new method enables phase-resolved detection of terahertz pulses using standard sCMOS equipment while achieving sample measurement times of less than one second with a precision error of less than 0.6%.
