Determine layer unique refractive index and thickness
with MP-SPR

Application Note #128

Langmuir-blodgett


Figure 4. Illustration of the two wavelength analysis principle. Black and orange line are RI – d continuum answers for both of the wavelengths. Dashed line is sifted curve based on the dRI/dλ value, which enables a unique solution for the thickness and RI.

Multi-Parametric Surface Plasmon Resonance (MP-SPR) can be used to determine unique thickness and refractive index (RI) of ultrathin films without prior knowledge of the RI or the thickness of the layer. Polyelectrolyte multilayer was measured using MP-SPR two wavelength method and analysed by LayerSolver™ software module. Thickness of 5 bilayers was found to be 16.8nm and RI 1.48 at 785nm.

Recommended instrument for this application:

200_otso_small.jpg 400_KONTIO_LOGO_24012019_cropped.jpg 210_vasa_small.jpg 410A_KAURIS_instrument.jpg  220A_naali_small.jpg 420_ilves_small.jpg
200 OTSO 400 KONTIO 210A VASA  410A KAURIS  220A NAALI 420A ILVES 
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Further reading

  • If you are interested in reading more about in situ and ex situ methods and measurements, see AN#127, AN#139 and AN#150.

  • Do you want to find out how to calculate thickness out of MP-SPR measurements? Click here.
  • Do you want to see how MP-SPR instruments work? Click here.

  • Do you want to see MP-SPR instruments comparison? Click here.

  • Here are a few publications you can have a look at.

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