GC_draw.lsf

# 2D Grating Coupler Model

# Draw GC
redrawoff;
gap=period*(1-ff); # etched region of the grating

# add GC base
addrect;
set('name','GC_base');
set('material',material);
set('x max',(gc_number+1)*period);
set('x min',0);
set('y',0.5*(thick_Si-etch_depth));
set('y span',thick_Si-etch_depth);

# add GC teeth;
for(i=0:gc_number)
{
  addrect;
  set('name','GC_tooth');
  set('material',material);
  set('y',0.5*thick_Si);
  set('y span',thick_Si);
  set('x min',gap+i*period);
  set('x max',period+i*period);
}
selectpartial('GC');
addtogroup('GC');


# draw silicon substrate;
addrect;
set('name','Si_sub');
set('material','Si (Silicon) - Dispersive & Lossless');
set('x max',30e-6);
set('x min', -20e-6);
set('y',-1*(thick_BOX+0.5*Si_substrate));
set('y span',Si_substrate);
set('alpha',0.2);

#draw burried oxide;
addrect;
set('name','BOX');
set('material','SiO2 (Glass) - Const');
set('x max',30e-6);
set('x min',-20e-6);
set('y min',-thick_BOX);
set('y max',thick_Clad);
set('override mesh order from material database',true);
set('mesh order',3);
set('alpha',0.3);

#draw waveguide;
addrect;
set('name','WG');
set('material','Si (Silicon) - Dispersive & Lossless');
set('x min',-20e-6);
set('x max', 0);
set('y',0.11e-6);
set('y span',0.22e-6);