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Wave Optics Reflectance Signal - Strange Oscillation

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I am trying to simulate the spectral response of an optical microcavity, and I've noticed a strange behavior in the reflectance vs wavelength plot.

The model contains a Al2O3 buffer in front of the actual microcavity structure, and if the thickness of this buffer is increased, the reflectance spectrum becomes quite noisy, especially at lower wavelengths. Attached are images illustrating the behavior.

I'm using frequency dependent n and k for all materials, periodic boundary conditions on the sides (perpendicular to the wave propagation direction), and ports as the source.

I would greatly appreciate any help diagnosing this issue.


1 Reply Last Post 16.11.2016, 15:53 GMT-5
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Hello David Scripka

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Posted: 8 years ago 16.11.2016, 15:53 GMT-5
Dear David,

This is called Fresnel oscillations. If you simply write a solution of Maxwell`s equations for your system, you will probably get such oscillating solutions.

If you know russian you can find this problem in Grechko book.


Regards,
Eugene
Dear David, This is called Fresnel oscillations. If you simply write a solution of Maxwell`s equations for your system, you will probably get such oscillating solutions. If you know russian you can find this problem in Grechko book. Regards, Eugene

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