用激光自混合干涉测量扬声器的Q值  

Measuring Q factor of speaker with laser self-mixing interference

作　　者：胡险峰[1] 

机构地区：[1]四川大学物理科学与技术学院,四川成都610064

出　　处：《物理实验》2011年第4期18-20,23,共4页Physics Experimentation

摘　　要：用激光自混合干涉方法测量扬声器振动,从扬声器振动引起的自混合干涉信号测量扬声器振动速率.由正弦波激振扬声器测量振速的幅频特性曲线,谐波中包含扬声器谐振频率的方波激振扬声器测量振速衰减曲线,分别按谐振法和衰减法测量得到扬声器的品质因数约13.3和10.2.由于方波激励时扬声器有谐波振动成分,由方波激励获得的衰减曲线测量得到的品质因数要小些.激光自混合干涉方法可以不扰动且直接地测量扬声器振动的Q值.Vibration of speaker was measured by laser self-mixing interference.Vibration rates were measured from the signal of self-mixing interference caused by speaker vibrating.The curve of amplitude-frequency was measured at sinusoid signal stimulation.The attenuation curve of the vibration amplitude was measured at stimulation of square signal whose harmonic frequencies included the resonant frequency of the speaker.The Q factor of the speaker was about 13.3 and 10.2,respectively measured by resonance method and attenuation method.The Q factor by attenuation method was smaller than that by resonance method,because there were more harmonic components for the square signal stimulation.Laser self-mixing interference method could be used to measure Q factor of speaker vibration directly without fluctuation.

关 键 词：振动测量 品质因数 激光二极管 自混合干涉 

分 类 号：TH744.3[机械工程—光学工程]