function FUNC_DEVICE_2X2(instPath)
{
    inst = read(instPath);
    eval(inst);
    
    jsonload(jsonPath);
    
    HwaferMax = 0;
    for(idx=1;idx<=length(layers.numbers);idx=idx+1){
        
        if (iscell(layers.numbers)){
        layer = num2str(layers.numbers{idx}) + ":" + num2str(layers.datatype{idx});}
        
        else{
        layer = num2str(layers.numbers(idx)) + ":" + num2str(layers.datatype(idx));}
        
        if (iscell(layers.heights)){
            Hwafer = layers.heights{idx}*1e-6;}
        else{
            Hwafer = layers.heights(idx)*1e-6;}
                
        
        gdsimport(gdspath, devName, layer,wafer.material, 0, Hwafer);
        #gdsimport(folder + devName + ".gds", devName, layer,wafer.material, 0, Hwafer);
        #set("name","device");

        if (Hwafer>HwaferMax)
        {
            HwaferMax = Hwafer;
        }
    }
    
    ## output ports

    # HwaferMax = Hwafer;
    zOffset = HwaferMax/2*1e+6;
    mx_simu_area('FDTD',[FDTD.x,FDTD.y,FDTD.z+zOffset]*1e-6,
                        [FDTD.dx,FDTD.dy,FDTD.dz]*1e-6,FDTD.mesh_order,[40,40,40]*1e-6,'PML',10e+5);
    
    portList = ports.names;
    
    for (idx=1;idx<=length(portList);idx=idx+1)
    {
        portName = portList{idx};
    
        eval("port_struct = ports."+portName+";");
        
        if (port_struct.a < 0) { port_struct.a = port_struct.a + 360; }
        
        if ( 45<=port_struct.a and port_struct.a<135 )
            {
                portsType = -2;     
                portsSZ = [port_struct.width,0,port_struct.height]*1e-6;     
            }
        else if (225<=port_struct.a and port_struct.a<315)
            {
                portsType = 2;     
                portsSZ = [port_struct.width,0,port_struct.height]*1e-6;     
            }
        
        else if (135<=port_struct.a and port_struct.a<225)
            {
                portsType = 1;     
                portsSZ = [0,port_struct.width,port_struct.height]*1e-6;     
            }
        
        else if (port_struct.a<45 or port_struct.a>=315)
            {
                portsType =-1;
                portsSZ = [0,port_struct.width,port_struct.height]*1e-6;     
            }
            
        
        mx_power_monitor(portName,[port_struct.x,port_struct.y,zOffset]*1e-6,
                            portsSZ,abs(portsType)) ;  
        set("override global monitor settings",1);
        set("frequency points",FDTD.Trans_sample_points);
        
        mx_mode_expansion(portName+'_modes',[port_struct.x,port_struct.y,zOffset]*1e-6,
                                portsSZ,abs(portsType),0,
                                [abs(port_struct.radius)*1e-6,
                                sign(port_struct.radius)*sign(portsType)*180],1,FDTD.wl*1e-6,portName); 

                                
        if (iscell(modes)){modes = [modes{1}];}

        set("selected mode numbers",modes);
        
        if ( abs(port_struct.a) <= 45 or abs(port_struct.a) > 315)
        {
            set('theta',port_struct.a);   
            set('phi',0);
        }

        else if ( abs(port_struct.a) > 135 and abs(port_struct.a) <= 225)
        {
            set('theta',port_struct.a);   
            set('phi',0);
        }
                
        else{
            set('theta',90-port_struct.a);   
            set('phi',90);    
        }
        
        
        }
        
    mx_power_monitor('z1',[mont.z1.x,mont.z1.y,zOffset]*1e-6,
                            [mont.z1.dx,mont.z1.dy,0]*1e-6,3) ;
    set("override global monitor settings",1);
    set("frequency points",FDTD.Field_sample_points);
    
    ## adding input ports 
    
    input_struct = ports.a1;
    if (input_struct.a < 0) { input_struct.a = input_struct.a + 360; }
    
    if ( 45<=input_struct.a and input_struct.a<135 )
    {
        inputType = -2;     
        portsSZ = [input_struct.width,0,input_struct.height]*1e-6;     
        input_theta = 90-input_struct.a;   
        input_phi = 0;   
    }
    else if (225<=input_struct.a and input_struct.a<315)
    {
        inputType = 2;     
        portsSZ = [input_struct.width,0,input_struct.height]*1e-6;  
        input_theta = 270-input_struct.a;   
        input_phi = 0;    
    }
    
    else if (135<=input_struct.a and input_struct.a<225)
    {
        inputType = -1;     
        portsSZ = [0,input_struct.width,input_struct.height]*1e-6;  
        input_theta = input_struct.a - 180;   
        input_phi = 0;   

    }
    
    else if (input_struct.a<45 or input_struct.a>=315)
    {
        inputType = 1;
        portsSZ = [0,input_struct.width,input_struct.height]*1e-6; 
        input_theta = input_struct.a;   
        input_phi = 0;     
    }
        
    mx_mode_source('a1_input',[input_struct.x,input_struct.y,zOffset]*1e-6,
                            portsSZ,inputType,0,
                            [abs(input_struct.radius)*1e-6,sign(input_struct.radius)*sign(inputType)*90],FDTD.sourceMode,FDTD.wl*1e-6);
    set("theta",input_theta);
    set("phi",input_phi);

    ## setting FDTD configurations
    
    select("FDTD");
    
    set("background material",clad.material);
    
    if (FDTD.GPUOn == 1){

        setnamed("FDTD", "express mode", true);    
        setresource("FDTD","GPU", true);
        setresource("FDTD", 1, "GPU Device", "Auto");
        set('z min bc','PML');
        }
    else {
        setnamed("FDTD", "express mode", false);    
        setresource("FDTD","GPU", false);

        if (length(layers.numbers)==1){
            set('z min bc','symmetric');}
            else {set('z min bc','PML');}

    }
    
    save(folder+"\\"+devName+"_simu.fsp");
    #save("DEVICE_2X2.fsp");
    
}

function DATA_RETRIEVE_DEVICE_2X2(instPath)
{

    inst = read(instPath);
eval(inst);
jsonload(jsonPath);

portList = ports.names;

save_cmd = "";

for (idx=1;idx<=length(portList);idx=idx+1)

{
    portData = struct;
    portData.name = portList{idx};
    
    portData.power = getresult(portData.name,"T");
    portData.modes = getresult(portData.name+"_modes","expansion for input");
    E = getresult(portData.name,"E");
    H = getresult(portData.name,"H");
            
    x = E.x;
    y = E.y;
    z = E.z;
    
    cx = floor(length(x)/2)+1;
    cy = floor(length(y)/2)+1;
    cz = floor(length(z)/2)+1;
    
    ## wavelength length
    sz_wl = size(E.E,4);
    
    step = floor((sz_wl-1)/(FDTD.Field_sample_points-1));
    idxSect = [1:step:sz_wl+1];
    
    E_save = E;
    H_save = H;
    
    E_save = matrixdataset;
    E_save.addparameter("x",E.x);        
    E_save.addparameter("y",E.y);        
    E_save.addparameter("z",E.z);        
    E_save.addparameter("lambda",E.lambda(1:step:end));        
    E_save.addattribute("E",E.E(:,:,:,1:step:end,:));        
            
    H_save = matrixdataset;
    H_save.addparameter("x",H.x);        
    H_save.addparameter("y",H.y);        
    H_save.addparameter("z",H.z);        
    H_save.addparameter("lambda",H.lambda(idxSect));        
    H_save.addattribute("H",H.H(:,:,:,idxSect,:));          
     
    portData.E = E_save;          
    portData.H = H_save;          
    
    ## Center electric field of the monitor
    Ecenter = E.E(cx,cy,cz,:,:); ## (x,y,z,wl,Ex/Ex/Ez)
    Hcenter = H.H(cx,cy,cz,:,:); ## (x,y,z,wl,Ex/Ex/Ez)
    portData.Ecenter = Ecenter;          
    portData.Hcenter = Hcenter;          
    
    eval(portData.name + " = portData;");
    save_cmd = save_cmd + portData.name + ",";
    
    }

if (find(portList=="a1") and find(portList=="b1")){
    Ephase_11 = unwrap(angle(b1.Ecenter) - angle(a1.Ecenter));
    Hphase_11 = unwrap(angle(b1.Hcenter) - angle(a1.Hcenter));
    save_cmd = save_cmd + "Ephase_11" + "," + "Hphase_11" + ",";
    
    }

if (find(portList=="a2") and find(portList=="b2")){
    Ephase_22 = unwrap(angle(b2.Ecenter) - angle(a2.Ecenter));
    Hphase_22 = unwrap(angle(b2.Hcenter) - angle(a2.Hcenter));
    save_cmd = save_cmd + "Ephase_22" + "," + "Hphase_22" + ",";
    }

if (find(portList=="a1") and find(portList=="b2")){
    Ephase_12 = unwrap(angle(b2.Ecenter) - angle(a1.Ecenter));
    Hphase_12 = unwrap(angle(b2.Hcenter) - angle(a1.Hcenter));
    save_cmd = save_cmd + "Ephase_12" + "," + "Hphase_12" + ",";
    }

if (find(portList=="a2") and find(portList=="b1")){
    Ephase_21 = unwrap(angle(b1.Ecenter) - angle(a2.Ecenter));
    Hphase_21 = unwrap(angle(b1.Hcenter) - angle(a2.Hcenter));
    save_cmd = save_cmd + "Ephase_21" + "," + "Hphase_21" + ",";
    }    

z1= struct;
z1.E = getresult("z1","E");
z1.H = getresult("z1","H");
Ex = getresult("z1","Ex");
Ey = getresult("z1","Ey");
Ez = getresult("z1","Ez");

savefname = devName+"_results.mat";

#matlabsave(savefname,b1,b2,z1);

eval("matlabsave(savefname,"+save_cmd+"z1);");
    
    
    }