{"id":361345,"date":"2024-04-09T14:45:16","date_gmt":"2024-04-09T14:45:16","guid":{"rendered":"\/forum\/forums\/topic\/lumerical-script-and-fdtd-simulation-ports\/"},"modified":"2024-04-09T15:13:41","modified_gmt":"2024-04-09T15:13:41","slug":"lumerical-script-and-fdtd-simulation-ports","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/lumerical-script-and-fdtd-simulation-ports\/","title":{"rendered":"Lumerical script and FDTD simulation ports"},"content":{"rendered":"

I am trying to simulate tilted subwavelength gratings. I have few questions regarding the simulation,<\/p>\n

    \n
  1. How do i place the input and output ports? The posted picture is XY view. Should i rotate ports with respect to the tilt angle?<\/li>\n
  2. How do i place access input and output waveguides? Should i tilt them with respect to te SWG tilt?<\/li>\n
  3. \n

    This is my code to create SWG:<\/p>\n

    m = (wg_width-width_in)\/taper_len; #Taper slope<\/p>\n

    b = width_in – (x0*m); #Taper width at x = 0<\/p>\n

     <\/p>\n

    num_periods = floor(taper_len\/period); #Number of SWG segments in the taper<\/p>\n

    period = period + (mod(taper_len,period)\/num_periods); #Adjusts SWG period so there is an integer number of periods in the taper length<\/p>\n

    segment_width = dc*period*1; #Longitudinal thickness of SWG segments<\/p>\n

     <\/p>\n

    x = x0 + (period\/2); #Starting position<\/p>\n

    #x = -1*taper_len-0.5*period;<\/p>\n

     <\/p>\n

    addstructuregroup;<\/p>\n

    set(‘name’,’swg1′);<\/p>\n

    set(‘x’,0e-06);<\/p>\n

    set(‘y’,0e-06);<\/p>\n

    set(‘z’,0e-6);<\/p>\n

     <\/p>\n

    for(i = 1:num_periods) {<\/p>\n

    width = m*x + b; #Calculate taper width at current position<\/p>\n

     <\/p>\n

    addrect;<\/p>\n

    set(‘name’,’seg_’+num2str(i));<\/p>\n

    set(‘material’,coremat);<\/p>\n

    set(‘x’,x); #Set x position based on current SWG segment<\/p>\n

    set(‘x span’,segment_width); #Set longitudinal thickness based on SWG period and duty cycle<\/p>\n

    set(‘y’,0e-06);<\/p>\n

    set(‘y span’,width); #Set transverse width based on taper width at this x position<\/p>\n

    set(‘z min’,-0.5*T);<\/p>\n

    set(‘z max’,0.5*T); #Assuming 220 nm SOI platform<\/p>\n

    select(‘seg_’+num2str(i));<\/p>\n

    set(‘second axis’,’z’);<\/p>\n

    set(‘rotation 2’, -tilt);<\/p>\n

    addtogroup(‘swg1’);<\/p>\n

     <\/p>\n

    x = x + period; #Increment to next SWG segment<\/p>\n

    }<\/p>\n

     <\/p>\n<\/li>\n<\/ol>\n

    <\/p>\n","protected":false},"template":"","class_list":["post-361345","topic","type-topic","status-closed","hentry","topic-tag-fdtd","topic-tag-FDTDgeometry-1","topic-tag-lumerical","topic-tag-LumericalFDTD-1","topic-tag-script"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t