Learning Forum

[Choyunho]

안녕하세요

FDTD 에서 Analysis group에 있는 Qanalysis tool 사용중에 궁금한것이 있어서 질문드립니다.

[gsun]

Hi，@Choyunho ，Sorry to reply you late. Shin-Sung now is taking more management responsibilities, I will try to help you through google translation. If possible, please submit your questions in English in the English Forum.
It seems that you want to have a contour map of Q vs. height and frequency. In the analysis group you have set the range from 300-400THz, however, the Q analysis gives different starting frequency/wavelength, causing the problem of contour mapping. If this is the question, then here is my answer:
Q and its correspondent frequency/wavelength are device's properties. If the height is changed, its resonant property may change. This is why you got different results. The current Q analysis group uses this
resonances = findresonances(t_cut,signal_cut,[f_min,f_max]);
to find the resonance. So if the resonance changes, the resulting resonant frequency/wavelength will change.

Since the above function only gives the result at the resonance, no values at off-resonance. it can be challenge to map the result discretely for continuous change or shift of the resonant frequencies.

To get the mapping, you may try some (complicated) manipulations:
1: record the Q analysis results from sweep, and then post-process the data: create a matrix to accommodate all possible resonate frequencies, and Qs.
2: use FFT, or CZT for that specific frequency rang, and get the intensity map first. Usually the higher intensity means higher Q. However, you will need to get the Qs at the different wavelength. Currently we do not have a script command to get Q at the given wavelength. It may end up the similar thing as #1.
You may just track one dominate resonance for simplification.
Lastly, you may have two plots instead of mapping: resonant frequency vs height, and Q vs height. This can greatly simply the script.