碳纳米管应变传感器的性能分析：实验偏振模式的影响机制

碳纳米管作为一种拉曼力学传感介质具有优异的力学性质及共振、偏振拉曼特性。将碳纳米管散布在基体材料中，即可实现局部应力/应变的测量。受到光学衍射极限的限制，常规的远场拉曼光谱得到的是一定区域内众多碳管的平均散射信息。本文综合考虑了采样点内各方向碳管的影响，并对碳管散射的共振状态、碳管的分布状态、拉曼系统的偏振构型及偏振方向等实验因素对碳纳米管应变传感器性能的影响进行了深入分析，采用分峰和重构的方法定量地给出了不同实验模式下采样点内的拉曼信息组成以及各种实验模式的测量精度。分析和对比表明，采用双偏振构型且偏振方向沿荷载施加方向时的测量精度最高，即最优的实验模式。

Performance Analysis of Carbon Nanotube Strain Sensor: Influence Mechanism of Polarization Mode

As a sensing media in Raman mechanics, CNTs have many excellent mechanical properties and resonance and polarization Raman characteristics. Local stress/strain measurement can be realized by dispersing carbon nanotubes in matrix material. Limited by optical diffraction, conventional far-field Raman spectra can only give the average scattering information of many CNTs in a certain area. In this paper, taking into account the influence of carbon nanotubes in each direction at sampling points, the influence of many experimental factors including the resonance scattering state of CNTs, the distribution state of CNTs, the polarization configuration of Raman system and the polarization direction etc. on the performance of CNT strain sensor was analyzed. The composition of Raman information in the sampling point and the measurement accuracy of different experiment modes are given quantitatively by using the method of peak separation and reconstruction. Through analysis and comparison among different modes, the most optimal experimental mode is double-polarization along loading direction.