高分辨太赫兹衰减全反射频域光谱系统

High resolution Attenuated Total Reflection terahertz frequency-domain spectroscopy

摘要:

由于水对太赫兹(THz)波具有强烈的吸收，含水样本的太赫兹光谱检测面临重大挑战。为解决太赫兹光谱对含水样本的高灵敏检测问题，本文提出并实验验证了一种太赫兹衰减全反射(ATR)的高分辨频域光谱系统。该系统采用创新式光混频相干检测技术，获得了出色的动态范围和分辨力性能，在0.3~1.2 THz范围内，峰值动态范围超过100 dB，频率分辨力高达100 MHz。创新式的ATR架构有效提升了灵敏度，在对不同浓度α-乳糖水溶液的实验测量中，实现了对水溶液样本的直接、精确定量检测。

Abstract:

Due to the strong absorption of terahertz(THz) by water, the detection of terahertz spectroscopy for aqueous samples faces significant challenges. To address the issue of high-sensitivity detection of aqueous samples using terahertz spectroscopy, this paper proposes and experimentally verifies a high-resolution frequency-domain spectroscopy system based on terahertz Attenuated Total Reflection(ATR). The system employs an innovative optical heterodyne coherent detection technique, achieving excellent dynamic range and resolution performance. Within the range of 0.3 to 1.2 THz, the peak dynamic range exceeds 100 dB, and the frequency resolution reaches up to 100 MHz. The innovative ATR architecture effectively enhances sensitivity, and in experimental measurements of aqueous solutions with different concentrations of α-lactose, the system has realized direct and accurate quantitative detection of the aqueous samples.