fdtd, nonlinear

时间：03-31 整理：3721RD 点击：

can anyone talk about fdtd for nonlinear simulation?
most of the topic is about linear domain, how about nonlinear case.
how to embed the nonlinear in UPML FDTD code?

any ideas

i hope seen the difference also

You should use the CPML from Gedney, since this kind of Perfectly matched layer is independent of the material properties at the interface.

that is nice of you.
btw, should the nonlinear code also run in the region of PML?

Added after 19 minutes:

in nonlinear medium, how to calculate the time-averaged Poynting vector?
as the power related to local index of refraction.

I think PML and UPML can handle inhomogeneous medium as well, by normalizing epsilon by the relative permittivity [ 2nd-FDTD book Toflove, page304, eq.7.52]

It really depends how you are modelling the nonlinear behaviour.
I have not heard about any algorithms which allows to put
non-linear materials into the boundary.

Basically, since modelling non-linearity is much harder than linear
materials youwould have to know exactly which model you will be using.

i have been made my program to simulate optical fiber in linear and nonlinear case by BOR-FDTD and i used it to simulat Fiber Bragg Grating FBG and the results
in my papers in this link

https://www.edaboard.com/viewtopic.p...793&highlight=

thanks

I think PML and UPML can handle inhomogeneous medium as well, by normalizing epsilon by the relative permittivity [ 2nd-FDTD book Toflove, page304, eq.7.52]

thank you for your information. but how to decide the weight coefficient between Raman scatter effet and Kerr effect.

Added after 1 minutes:

I think PML and UPML can handle inhomogeneous medium as well, by normalizing epsilon by the relative permittivity [ 2nd-FDTD book Toflove, page304, eq.7.52] PML is just the topic keyword for nearly perfect absorption. UPML is a specific technic to get a nearly perfect absorption. Achieving nearly perfect absorption for inhomoheneous media is not difficult to handle for every implemented absorption method (Split-Field PML, Uniaxial PML, Convolutional PML), but as far as you go into dispersive materials you should avoid Split-Field PML and Uniaxial PML, because you have to derive and implement for every dispersive media a special suited algorithm for that media. Choosing the Convolutional PML (3rd Editition Taflove) from Gedney, you got one algorithm for every dispersive media.
Thank you for your suggestion

Added after 1 hours 59 minutes:

does anyone have 3rd Edition Taflove?

hi,

the weight coefficient between Raman scatter effect and Kerr effect in most cases for optical fiber is equal 0.7

thanks