Menu

Discussion Forum

New Discussion
Filtern

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 The information provided may be out of date.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.

Reflectance / Transmittance calculation using PORT

Posted 09.01.2013, 01:53 GMT-5 RF & Microwave Engineering Version 4.3a 5 Replies

Dong-yeong Kim
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hello all

I want to calculate effect of nanostructure on reflectance and transmittance.

As a starting point, I have refered "Fresnel equation" library.
Without any nanostructure, the calculated reflectance is well matched with theorectical value!
So.. one thing I want to know is that the same port boundary condition can be applied to a model system with 3D nano structure? (Simply, air/Nanostructures on substrate/substrate)

Also, I want to calculate the reflectance using input and output power.
Output power can be calculated using integration of time-averaged power outflow (nPoav).
However, I don't know how to know incident power when I use scattering boundary condition, or electric field condition.
Would you comment on this?

<Summary>
1. Using same model of "Fresnel equation" library, can reflectance of a system with 3D nano structure be calculate?
2. How can I calculate incident power of light, when I use electric field boudnary condition?

Thanks!

Dong-yeong Kim
5 Replies Last Post 18.06.2013, 02:50 GMT-4
Alexander Kuznetsov
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 09.01.2013, 12:37 GMT-5
1. Yes, generally
2. Electric field BC won't give you the correct solution. Only scattering BC will work.
1. Yes, generally 2. Electric field BC won't give you the correct solution. Only scattering BC will work.
Dong-yeong Kim
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 09.01.2013, 20:00 GMT-5
Thanks sir.

I wanna ask you 3 more things.

1. As far as I know, there are 3 ways to generate electric field.
- Scattering boundary condition
- Electric field
- Port
Could you explain the differences between them?

2. Many libraries are using Floquet periodicity for imposing periodic boundary condition.
In my humble opinion, effect of "Floquet periodicity option" and "Continuity option" might be same.
Is it right?

3. For periodicity, PEC(PMC) condition can be used when electric(magnetic) field is normal to surface.
So.. if field is not perpendicular to a certain surface, I should use a periodic condition instead of PEC/PMC.
Is it also right?


I have had difficulty choosinig boundary conditions. :(

Thanks sir. I wanna ask you 3 more things. 1. As far as I know, there are 3 ways to generate electric field. - Scattering boundary condition - Electric field - Port Could you explain the differences between them? 2. Many libraries are using Floquet periodicity for imposing periodic boundary condition. In my humble opinion, effect of "Floquet periodicity option" and "Continuity option" might be same. Is it right? 3. For periodicity, PEC(PMC) condition can be used when electric(magnetic) field is normal to surface. So.. if field is not perpendicular to a certain surface, I should use a periodic condition instead of PEC/PMC. Is it also right? I have had difficulty choosinig boundary conditions. :(
Alexander Kuznetsov
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 10.01.2013, 13:51 GMT-5
1. Electric field BC - you simply specify total electric field at the boundary. Since you generally don't know the reflected field, you can't use it
Scattering BC - to launch plane waves
Port BC - to launch plane waves as well as any other. As a benefit, reflection coefficients are calculated for you.

2. Floquet BC is more general since it takes care of phase shift at the boundary. Continuity BC doesn't.

3. No. You should use Floquet. I'd suggest using it always, even when PEC/PMC would work.
1. Electric field BC - you simply specify total electric field at the boundary. Since you generally don't know the reflected field, you can't use it Scattering BC - to launch plane waves Port BC - to launch plane waves as well as any other. As a benefit, reflection coefficients are calculated for you. 2. Floquet BC is more general since it takes care of phase shift at the boundary. Continuity BC doesn't. 3. No. You should use Floquet. I'd suggest using it always, even when PEC/PMC would work.
Dong-yeong Kim
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 10.01.2013, 19:45 GMT-5
Thanks a lot!

This is a big helpful to me.
Thanks a lot! This is a big helpful to me.
Alice Miles
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 18.06.2013, 02:50 GMT-4

Hello all

I want to calculate effect of nanostructure on reflectance and transmittance.

As a starting point, I have refered "Fresnel equation" library.
Without any nanostructure, the calculated reflectance is well matched with theorectical value!
So.. one thing I want to know is that the same port boundary condition can be applied to a model system with 3D nano structure? (Simply, air/Nanostructures on substrate/substrate)

Also, I want to calculate the reflectance using input and output power.
Output power can be calculated using integration of time-averaged power outflow (nPoav).
However, I don't know how to know incident power when I use scattering boundary condition, or electric field condition.
Would you comment on this?

<Summary>
1. Using same model of "Fresnel equation" library, can reflectance of a system with 3D nano structure be calculate?
2. How can I calculate incident power of light, when I use electric field boudnary condition?

Thanks!

Dong-yeong Kim




I am a newbie in this field. I want to obtain reflectance and absorption spectra for a substarte. Can you tell me which module to use..?? Probably some link which gives step by step guidance.. ?

Thanks

[QUOTE] Hello all I want to calculate effect of nanostructure on reflectance and transmittance. As a starting point, I have refered "Fresnel equation" library. Without any nanostructure, the calculated reflectance is well matched with theorectical value! So.. one thing I want to know is that the same port boundary condition can be applied to a model system with 3D nano structure? (Simply, air/Nanostructures on substrate/substrate) Also, I want to calculate the reflectance using input and output power. Output power can be calculated using integration of time-averaged power outflow (nPoav). However, I don't know how to know incident power when I use scattering boundary condition, or electric field condition. Would you comment on this? 1. Using same model of "Fresnel equation" library, can reflectance of a system with 3D nano structure be calculate? 2. How can I calculate incident power of light, when I use electric field boudnary condition? Thanks! Dong-yeong Kim [/QUOTE] I am a newbie in this field. I want to obtain reflectance and absorption spectra for a substarte. Can you tell me which module to use..?? Probably some link which gives step by step guidance.. ? Thanks

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