作者s055072 (哈利)
看板Physics
标题[问题] paper内容看不懂 有关光学
时间Sun May 9 23:56:21 2010
内容是这样
These data represent the total amount of the transmitted light
with both the propagating and evanescent light modes.
她量测了一张近场光学图像有
包含propagating and evanescent light modes
As the evanescent modes are characterized by an in-plane
component of the wave vector (k平行) larger than its norm
and as the light intensity is periodic for each value of k平行,
the local distribution of evanescent modes can be extracted
by fast Fourier transformation (FFT) using a high-pass filter
with a cut-off frequency of 2/波长 which corresponds to
evanescent modes in air.
我想问的是为什麽
只要做FFT也就是使用一个high-pass filter去处理整个光场图像
就可以得到evanescent mode的光??
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※ 发信站: 批踢踢实业坊(ptt.cc)
◆ From: 140.113.244.111
1F：推 mingweii:因为只要frequency满足sqrt(fx^2+fy^2)>1/lambda, 则其 05/10 11:14
2F：→ mingweii:angular spectrum的transfer function (exp项)的指数会随 05/10 11:15
3F：→ mingweii:传播方向衰减, 可以看goodman的Fourier Optics chapter 3 05/10 11:15
4F：→ mingweii:这样的衰减效应就是evanescent mode 05/10 11:16