基于THz-QCL自混合干涉的运动传感

Motion sensing based on Self-Mixing interferometry with THz-QCL

基于自混合干涉效应的太赫兹量子级联激光器(THz-QCL)相干测量系统是一种极其灵敏的传感系统。相比于传统的激光测速技术,自混合干涉具有光路自准直、无需额外光电探测器和混频器等优势,使系统的结构更加紧凑;而且,使用太赫兹波进行相干测量,有望提升测速上限。本文采用THz-QCL的自混合干涉技术,研究了系统对于两独立运动目标物的非线性动力学响应特性,给出了自混合信号的多普勒频谱,并通过频谱分析,获得了两目标物的运动速率及方向。研究结果证实了利用THz-QCL自混合干涉系统对目标物进行运动传感的可行性,为高速运动的多目标物测速提供了新的技术手段。

Coherence measurement system based on Self-Mixing(SM)interferometry with a Terahertz Quantum Cascade Laser(THz-QCL)has been demonstrated to be a highly sensitive sensor.Compared with traditional laser Doppler velocimetry,it has the advantages of self-collimation and eliminating the need for a separate photodetector and mixer,which makes the system more compact;moreover,the exploitation of terahertz source is expected to improve the upper limit of velocity measurement.In this paper,the nonlinear dynamic response to the motion of two independent targets is investigated,which manifests itself in the SM interferometric signal.Through the spectrum analysis of the SM signal,velocities and directions of the two targets are obtained.The research results demonstrate the feasibility of using THz-QCL SM interferometric system to sense the motion of targets,and provide a novel technique for laser Doppler velocity measurement of multiple targets with high speed.