% this is geometry of rib waveguide covered by SiO2

onGaAsSubstrte='n';   % otherwise on Si substrate

%%%%%%%%%% main !!!!!!!!!!!!!!!!!!!!!!!!!!
tCore=0.25; %um
tClad=1.3; %um
etchDepth=tCore;  %0.2; %um
wireWidth=0.8;

%%%%%%%%%%%%%%%%%%%%%%%%% 
ButFillet=0.001;
TopFillet=0.02;

if onGaAsSubstrte=='y'
xCore=0.3;
xClad=0.5;
onSiSubstrte='n';
else
    onSiSubstrte='y';
end

CoveredBySiO2='n';
SiO2Thickness=0.2; %um

CalculationWidth=wireWidth+2;
CutLinePos=-0.3;  % um position where transverse refractive index is calculated
AirAbove=0.5;   %um Air above


UseGaAs='n';
GaAsThickness=0.5;
if UseGaAs=='n'; GaAsThickness=0;end

disp('geometry  started')
%%%%%%%%%%%%%% geometry

if UseGaAs=='y';
    nAprox=(nAlGaAs(xClad,lambda)+nAlGaAs(xCore,lambda))/2;
else
   nAprox=(nSi(lambda)+nSiO2(lambda))/2 ;
   nAprox=2.8;
end
model.param.set('nAprox', num2str(nAprox),'aproximate of refractive index');

model.param.set('lambda', [num2str(lambda) '[um]'],'wavelength');

model.param.set('CoreThickness', [num2str(tCore) '[um]'],'thickness of AlGaAsCore');
model.param.set('AlGaAsCladThickness', [num2str(tClad) '[um]'],'thickness of AlGaAs clad');


if UseGaAs=='y'; model.param.set('GaAsThickness', [num2str(GaAsThickness) '[um]'],'thickness of sub (calculution window');end;

model.param.set('SiO2Cover', [num2str(SiO2Thickness) '[um]'],'thickness of SiO2 cover');

model.param.set('WireWidth',[num2str(wireWidth) '[um]'], 'width of main wire');
model.param.set('EtchingDepth',[num2str(etchDepth) '[um]'], 'should be larger than core');



model.param.set('CalculationWidth',[num2str(CalculationWidth) '[um]'], 'width of main wire');
model.param.set('AirAbove',[num2str(AirAbove) '[um]'], 'air above top of SiO2');


geom1 = model.geom.create('geom1', 2);
model.geom('geom1').lengthUnit([native2unicode(hex2dec('00b5'), 'Cp1252') 'm']);  % set length unit in um

% zero at boundary core and clad layers
if UseGaAs=='y'
% GaAs sub
r1=model.geom('geom1').feature.create('r1', 'Rectangle');
r1.set('size',{'CalculationWidth' 'GaAsThickness'});
r1.set('pos',{'-CalculationWidth/2' '-GaAsThickness-AlGaAsCladThickness'});
geom1.run
model.geom('geom1').feature().create('sel1', 'Selection');
model.geom('geom1').feature('sel1').selection('selection').set('r1',1);
end

% AlGaAs clad before etch
r2=model.geom('geom1').feature.create('r2', 'Rectangle');
r2.set('size',{'CalculationWidth' 'AlGaAsCladThickness'});
r2.set('pos',{'-CalculationWidth/2' '-AlGaAsCladThickness'});

% AlGaAs core before etch
r3=model.geom('geom1').feature.create('r3', 'Rectangle');
r3.set('size',{'CalculationWidth' 'CoreThickness'});
r3.set('pos',{'-CalculationWidth/2' '0'});

%etching rib
r4=model.geom('geom1').feature.create('r4', 'Rectangle');
r4.set('size',{'WireWidth' 'EtchingDepth'});
r4.set('pos',{'-WireWidth/2' 'CoreThickness-EtchingDepth'});

%etching rib
r5=model.geom('geom1').feature.create('r5', 'Rectangle');
r5.set('size',{'CalculationWidth' 'EtchingDepth'});
r5.set('pos',{'-CalculationWidth/2' 'CoreThickness-EtchingDepth'});
geom1.run;

model.geom('geom1').feature.create('dif1', 'Difference');
model.geom('geom1').feature('dif1').selection('input').set({'r5'});
model.geom('geom1').feature('dif1').selection('input2').set({'r4'});
model.geom('geom1').feature('dif1').set('keep', 'on');
geom1.run
model.geom('geom1').feature.create('fil2', 'Fillet');
model.geom('geom1').feature('fil2').selection('point').set('dif1', [3 5]);
model.geom('geom1').feature('fil2').set('radius', num2str(ButFillet));
% fil2 is what etched from gaas


model.geom('geom1').feature.create('dif1a', 'Difference');
model.geom('geom1').feature('dif1a').selection('input').set({'r5'});
model.geom('geom1').feature('dif1a').selection('input2').set({'r4'});

geom1.run;

% AlGaAs core after etch
model.geom('geom1').feature.create('dif2', 'Difference');
model.geom('geom1').feature('dif2').selection('input').set({'r3'});
model.geom('geom1').feature('dif2').selection('input2').set({'fil2'});

% AlGaAs cclad after etch
model.geom('geom1').feature.create('dif3', 'Difference');
model.geom('geom1').feature('dif3').selection('input').set({'r2'});
model.geom('geom1').feature('dif3').selection('input2').set({'dif1a'});

geom1.run;

model.geom('geom1').feature().create('sel2', 'Selection');
model.geom('geom1').feature('sel2').selection('selection').set('dif3',1);

model.geom('geom1').feature.create('fil1', 'Fillet');
model.geom('geom1').feature('fil1').selection('point').set('dif2', [3 5]);
model.geom('geom1').feature('fil1').set('radius', num2str(TopFillet));
geom1.run;

model.geom('geom1').feature().create('sel3', 'Selection');
model.geom('geom1').feature('sel3').selection('selection').set('fil1',1);

% SiO2 cover
 if CoveredBySiO2=='y'
r6=model.geom('geom1').feature.create('r6', 'Rectangle');
r6.set('size',{'WireWidth+2*SiO2Cover' 'EtchingDepth+SiO2Cover'});
r6.set('pos',{'-WireWidth/2-SiO2Cover' 'CoreThickness-EtchingDepth'});
geom1.run;
model.geom('geom1').feature.create('fil6', 'Fillet');
model.geom('geom1').feature('fil6').selection('point').set('r6', [1 2]);

model.geom('geom1').feature('fil6').set('radius', 'TopFillet');

r7=model.geom('geom1').feature.create('r7', 'Rectangle');
r7.set('size',{'CalculationWidth' 'SiO2Cover'});
r7.set('pos',{'-CalculationWidth/2' 'CoreThickness-EtchingDepth'});
geom1.run;

model.geom('geom1').feature.create('uni1', 'Union');
model.geom('geom1').feature('uni1').selection('input').set({'fil6' 'r7'});
model.geom('geom1').feature('uni1').set('intbnd', 'off');
geom1.run;

model.geom('geom1').feature().create('sel4', 'Selection');
model.geom('geom1').feature('sel4').selection('selection').set('uni1',1);
     end

% air



r8=model.geom('geom1').feature.create('r8', 'Rectangle');
r8.set('size',{'CalculationWidth' 'EtchingDepth+AirAbove'});
%r8.set('pos',{'-CalculationWidth/2' 'CoreThickness-EtchingDepth+SiO2Cover'});
r8.set('pos',{'-CalculationWidth/2' 'CoreThickness-EtchingDepth'});
geom1.run;

if CoveredBySiO2=='y'
model.geom('geom1').feature.create('copy1', 'Copy');
model.geom('geom1').feature('copy1').selection('input').set({'uni1'});
model.geom('geom1').feature.create('dif4', 'Difference');
model.geom('geom1').feature('dif4').selection('input').set({'r8'});
model.geom('geom1').feature('dif4').selection('input2').set({'copy1'});
geom1.run;

model.geom('geom1').feature().create('sel5', 'Selection');
model.geom('geom1').feature('sel5').selection('selection').set('dif4',1);
else
    model.geom('geom1').feature().create('sel5', 'Selection');
model.geom('geom1').feature('sel5').selection('selection').set('r8',1);
end

%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%% materials


%AlGaAs core
model.material.create('mat1');
if onGaAsSubstrte=='y';model.material('mat1').name('AlGaAs core');else; model.material('mat1').name('Si core');end
model.material('mat1').propertyGroup.create('RefractiveIndex', 'Refractive index');
if onGaAsSubstrte=='y';
    model.material('mat1').propertyGroup('RefractiveIndex').set('n', {num2str(nAlGaAs(xCore,lambda)')});
else
    model.material('mat1').propertyGroup('RefractiveIndex').set('n', {num2str(nSi(lambda)')});
end
model.material('mat1').selection.set([model.selection('geom1_sel3').entities(2);]);

%AlGaAs clad
model.material.create('mat2');
if onGaAsSubstrte=='y';model.material('mat2').name('AlGaAs clad');else;model.material('mat2').name('SiO2 clad');end
model.material('mat2').propertyGroup.create('RefractiveIndex', 'Refractive index');
if onGaAsSubstrte=='y';
model.material('mat2').propertyGroup('RefractiveIndex').set('n', {num2str(nAlGaAs(xClad,lambda)')});
else
    model.material('mat2').propertyGroup('RefractiveIndex').set('n', {num2str(nSiO2(lambda)')});
end

model.material('mat2').selection.set([model.selection('geom1_sel2').entities(2);]);

if UseGaAs=='y'
%GaAs core
model.material.create('mat3');
model.material('mat3').name('GaAs sub');
model.material('mat3').propertyGroup.create('RefractiveIndex', 'Refractive index');
model.material('mat3').propertyGroup('RefractiveIndex').set('n', {num2str(nAlGaAs(0,lambda)')});
model.material('mat3').selection.set([model.selection('geom1_sel1').entities(2);]);
end

%SiO2   cover
if CoveredBySiO2=='y'
model.material.create('mat4');
model.material('mat4').name('SiO2 cover');
model.material('mat4').propertyGroup.create('RefractiveIndex', 'Refractive index');
model.material('mat4').propertyGroup('RefractiveIndex').set('n', {num2str(nSiO2(lambda))});
model.material('mat4').selection.set([model.selection('geom1_sel4').entities(2);]);
end

%air
model.material.create('mat5');
model.material('mat5').name('air');
model.material('mat5').propertyGroup.create('RefractiveIndex', 'Refractive index');
model.material('mat5').propertyGroup('RefractiveIndex').set('n', {'1'});
model.material('mat5').selection.set([model.selection('geom1_sel5').entities(2);]);



%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%
% create mesh
%  create mesh
mesh1=model.mesh.create('mesh1', 'geom1');
meshSize=mesh1.feature('size');
meshSize.set('hauto', '2');
mesh1.feature.create('ftri1', 'FreeTri');
mesh1.run;
mesh1.data.transferMesh;

disp('geometry OK')