On Tue, 3 Apr 2007, liurj wrote:
I used meep to calculate field distribution in waveguide. At first, it can be seen that the field propagates in the waveguide. However, the field will dis p erse in the whole calculated zone finally. I don\'t know why, and can\'t find out the reason. I have tried to change the th ic kness and strength of PML, the position and frequency of source.
You put PML around the whole structure, which means that the waveguide modes are decaying along with everything else. What you want to do, instead, is to use periodic boundary conditions in the direction of the waveguide and PML absorbers only on the sides. This way, the waveguide mode will propagating without decaying (much), assuming it doesn't overlap (much) with the PML, whereas the radiative modes to the sides will decay.
See the example calculation of the waveguide modes and band diagram in the wiki:
http://ab-initio.mit.edu/wiki/index.php/Meep_Tutorial/Band_diagram%2C_resonant_modes%2C_and_transmission_in_a_holey_waveguide Steven _______________________________________________ meep-discuss mailing list [email protected] http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
