检测Doppler-free红外激光光声信号的两种方法

TWO METHODS FOR DETECTING DOPPLER-FREE INFRARED LASER OPTOACOUSTIC SIGNAL

讨论了检测Doppler-free红外激光光声信号的和频方法和差频方法,发现在用相同斩波叶片情况下,几乎对所有的斩波孔数比F_2/F_1差频方法在减少组合频率干扰、提高信噪比方面都好于或等于和频方法.

Both the sum and difference frequency methods for detection of the Doppler-free infrared laser optoacoustic signal are discussed. It is discovered that the difference frequency method is better than, or equal to the sum frequency method in terms of decreasing interference of the combination frequency and increasing signal-to-noise ratio when using the same chopping vane for almost all the ratios of chopping hole number F_2/F_1.