Reflectivity

[Jonathan Becker]

I’m beginning to use the 32-Bit version of OptiFDTD, and I’m trying to run a few basic simulations. However, I’ve had a pretty significant difficulty and perhaps someone can lend a hand. I ran a simple simulation with a plane wave moving through an air medium coming into contact with a dielectric block (glass). The known reflectivity of glass is about 4%. However, when I run the simulation (using the boundary conditions from the plane wave tutorial), the backscattered electric field has an amplitude of about .22. The forward scattered electric field is 1.18. The ration of the intensities here yields a result of about a 3% reflectivity. I wondered if anyone else has had a similar problem, and if there are any solutions?

[Ravil]

Hi Jonathan,

Without going deep into details, if I understood you correctly, you have a back scattered electric field with its amplitude of about 22% of incident light. Which makes your reflection coefficient equal to 0.22. It is known that the reflectivity (the ration of a reflected light intensity to an incident light intensity) is equal to squared reflection coefficient. Hence, for the case with your glass, the reflectivity will be in the vicinity of 4%.

[Ravil]

Not exactly sure how you have calculated a 3% reflectivity in your case for the second part of your question… Are you assigning any units for you electric fields?

[Jonathan Becker]

Ravil,

Thank you for your reply. I was actually looking for the ration of the intensities. However, I now realize I had misconstrued the incident intensity. When I take this into account, the result is much closer to the known result. Thank you again!

[Ravil]

You are welcome, Jonathan! As a forum member, I am glad that my guidance helped you in some way. Good luck with your work and Optiwave experience!

[Author]

Posts