Menu

Discussion Forum

New Discussion
Filter

Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Controlling size of background plane wave in optical scattering

Posted Aug 25, 2016, 10:11 a.m. EDT RF & Microwave Engineering, Materials, Modeling Tools & Definitions, Parameters, Variables, & Functions, Results & Visualization Version 4.3a 1 Reply

Rahim Leung
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hi,

I am currently working on modelling the optical scattering of a plane wave on a nanocircle. I require the plane wave to only excite a select region of space, and so I multiplied it with a rectangular function with the desired width. However, the results indicate that when multiplied with the rectangular function, there are diffraction like effects that affect the scattered field that are not present when rectangular function is not applied.

I have included two images of the scattered field norm: one is when the plane wave is truncated with a rectangular function, and one is with a plane wave of infinite extent in the y-direction.

How do I remove the unwanted effects from the results with the truncated plane wave?

Thanks!

Attachments:

1 Reply Last Post Aug 25, 2016, 10:37 p.m. EDT
Robert Koslover Certified Consultant
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 8 years ago Aug 25, 2016, 10:37 p.m. EDT
Instead of a rectangle, consider using a spatial windowing function that does not have such a sharp edge. Then you will get much less diffraction.

en.wikipedia.org/wiki/Window_function

Also, consider using Comsol's "Scattered-Field" formulation instead of the full field formulation.
Instead of a rectangle, consider using a spatial windowing function that does not have such a sharp edge. Then you will get much less diffraction. https://en.wikipedia.org/wiki/Window_function Also, consider using Comsol's "Scattered-Field" formulation instead of the full field formulation.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.

Suggested Content