Figure 3.

Plot of the harmonic ratios as a function of separation distance. The amplitude (A) ratios of the fundamental frequency to the 2^nd (circles), 3^rd (squares), and 4^th (triangles) harmonics are shown at each separation distance. The dashed lines represent the best fit lines, as determined through least squares fitting of the data to a two parameter exponential expression. Errors bars are smaller than the data points, and are a result of the 10 μV noise in the signal. The 5^th harmonic was excluded due to the weakness of the signal at the larger separation distances.