# Questions related to Poynting vector Pz

#1

Hello:

I am confused about the Poynting vector Pz in Mode solutions.

1. If I set the material RI as a real number, the calculated real(Pz) for mode1 to mode3 are all 0,why?
wg_2D_TM0_TE1_normal_grid_mesh_dy_10nm_material_real_value.lms (267.2 KB)

2. If I use the material in library, the calculated real(Pz) for mode1 to mode3 have some values. But the power transmission along propagation for mode2 is a negative value, while that for mode1 and mode3 are positive. Why the sign of transmission for different mode is different?
Pz.lsf (622 Bytes)
wg_2D_TM0_TE1_normal_grid_mesh_dy_10nm_material_library.lms (267.2 KB)

3. Is it possible for me to normalize the transmission power for each mode to 1?

Thank you!

#2

Hi @yahan

P2_x=pinch(real(P2.Px));

T2 = 0.5*integrate(P2_x,1:2,y,z); # power in watts

? 'T2='+num2str(T2);


In your scripts, you need to extract the Px value if you are integrating over the yz plane:

Doing so:

1. The values for transmissions are non-zero.
2. The values are all positive.
3. Please elaborate. You can multiply E and H fields by a constant to obtain a transmission of 1 if this is what you mean.

Thanks

#3

Thanks a lot!

Best,

Ya

On 11/14/2018 11:39，Behzad Support Khanaliloolumerical@discoursemail.com wrote：