Løkberg O J, Pedersen H M, Valø H, Wang G
Appl Opt. 1994 Aug 1;33(22):4997-5002. doi: 10.1364/AO.33.004997.
We separately measure the higher harmonics vibration patterns of a periodic vibrating object by using time-average TV holography and phase modulation. During measurements the frequency of the phase modulation is adjusted to each harmonic component while the excitation of the object is set low enough to record all components on the linear part of the fringe function. Using acoustical phase stepping and calibration of the fringe function, we compute the amplitude and phase distributions of the frequency component. We measure components up to the 65th harmonic by using square-wave excitation.
我们通过使用时间平均电视全息术和相位调制来分别测量周期性振动物体的高次谐波振动模式。在测量过程中，将相位调制的频率调整到每个谐波分量，同时将物体的激励设置得足够低，以便在条纹函数的线性部分记录所有分量。利用声学相位步进和条纹函数校准，我们计算频率分量的振幅和相位分布。我们通过使用方波激励来测量高达第65次谐波的分量。
