锁定放大器在光速测量中的应用  

Lock-in amplifier in light speed measurement

作　　者：徐英[1] 李柯[1] 

机构地区：[1]西南石油大学理学院,四川成都610500

出　　处：《物理实验》2008年第2期36-37,41,共3页Physics Experimentation

摘　　要：结合声光调制原理和锁定放大器的工作原理,设计了基于调制法的测量光速实验.通过测量和计算得出光速为2.993×108m/s和3.000×108m/s,与光在空气中的速度值2.997×108m/s相比,误差分别为0.13%和0.10%.此方法的优点是光速经过调制后,光的频率被调制为60～100MHz,使得光波长调制为3～5m,便于在实验室里进行光速测量.Using a combination of acousto-optic modulator and lock-in amplifier, a light speed measurement experiment is designed based on modulation method, the speed of light is measured to be 2. 993×10^8 m/s and 3. 000×10^8 m/s. Compared with the widely recognized value of 2. 998×10^8m/s in the air, the relative error is 0.13% and 0.10% . The advantage of this method is that by modulating the frequency of light to 60 MHz to 100 MHz, the optical wavelength is modulated to 3 m to 5 m, and then the light speed could be easily measured.

关 键 词：光速 声光调制 锁定放大器 

分 类 号：O431[机械工程—光学工程] TN76[理学—光学]