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hjskofficial
8 Posts |
 Posted - 02/20/2024 : 10:28:13 AM
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Origin Ver. and Service Release (Select Help-->About Origin): 2018
Operating System: Windows 10
I would like to fit a reflectance spectrum generated by surface plasmons in order to determine the dip value and full width at half minimum. The curve exhibits a non-symmetric dip, meaning that the left and right parts of the reflection dip are markedly different. Traditionally, surface plasmon-generated curves have been fitted using Gaussian or Lorentzian functions. However, in this case, neither Gaussian nor Lorentzian functions adequately capture the original curve. I also considered using the Fano function for fitting, but it can only be applied to spectra under conditions of mode coupling. The raw data for the curve can be downloaded via the following link. Does anyone know of an appropriate solution? Thank you.
https://drive.google.com/file/d/1xZVUTApTBJVJV8i5J4Ej-GyznJKN_65D/view?usp=sharing |
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YimingChen
1594 Posts |
Posted - 02/20/2024 : 12:13:10 PM
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If you just want to obtain the peak height and FWHM values, you may use the Quick Peak gadget.
James |
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hjskofficial
8 Posts |
Posted - 02/21/2024 : 04:58:55 AM
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Hi James,
Thank you very much for your solution. Additionally, could you please explain how the Quick Peak gadget determines the FWHM? I ask this question because there are differences between the left and right parts of the curve.
Best regards,
HJS
quote:
Originally posted by YimingChen
If you just want to obtain the peak height and FWHM values, you may use the Quick Peak gadget.
James
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YimingChen
1594 Posts |
Posted - 02/21/2024 : 08:28:08 AM
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Here the FWHM is not obtained by fitting the peak. It's the peak width at half the peak's maximum value.
James
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hjskofficial
8 Posts |
Posted - 02/22/2024 : 04:11:45 AM
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I see. Thank you very much for your reply. I have two more questions. First, why did the Local Points set to 20? And second, why did the baseline mode set to straight line?
HJS
quote:
Originally posted by YimingChen
Here the FWHM is not obtained by fitting the peak. It's the peak width at half the peak's maximum value.
James
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YimingChen
1594 Posts |
Posted - 02/22/2024 : 08:34:31 AM
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1. The curve exhibits some noise. I set the Local Points to 20 so that only one peak is detected.
2. Connecting the end points with a straight line is one approach to define baseline. But the choice of method may vary depending on the nature of the peak, and you may consider alternative approaches.
James |
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hjskofficial
8 Posts |
Posted - 02/26/2024 : 10:09:06 PM
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Hi James,
I see. Thank you very much for your explanation.
HJS
quote:
Originally posted by YimingChen
1. The curve exhibits some noise. I set the Local Points to 20 so that only one peak is detected.
2. Connecting the end points with a straight line is one approach to define baseline. But the choice of method may vary depending on the nature of the peak, and you may consider alternative approaches.
James
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Topic |
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A curve fitting problem of surface plasmon