clear all

visastring = "GPIB0::22::INSTR";
v_pwrmtr = visadev(visastring);
writeline(v_pwrmtr, "*IDN?");
answ = readline(v_pwrmtr);
disp(['Yay! We can talk to Instrument: ',char(answ)]);

% laser = Exfo_laser("mainframe_channel",3,"safety_mode",0,"connection_id",'15','lab_interface','gpib');
% laser.getLaserInfo();

L = OptLaserN7714A("GPIB0::20::INSTR");

% visastring = 'GPIB0::10::INSTR';
% v_lsr = visadev(visastring);
% writeline(v_lsr, "*IDN?");
% answ = readline(v_lsr);
% disp(['Yay! We can talk to Instrument: ',char(answ)]);

steps = 100;
wavelength_sweep = linspace(1554,1556,steps);
start_wavelength = wavelength_sweep(1);

% laser.setWavelength(start_wavelength);
L.setWavelength(start_wavelength,0);
% laser.setPower(0);
% laser.enableLaser();
L.setPower(0, true,0);


pwr_save = NaN(size(wavelength_sweep));
for l = 1:numel(wavelength_sweep)
    
    % 1) 
    % laser.setWavelength(wavelength_sweep(l));
    L.setWavelength(wavelength_sweep(l),0);
    %writeline(v_lsr, ['L=' num2str(wavelength_sweep(l))]);

    % 2) Set Wavelength of Power Meter
    t = string(['SENS2:POW:WAVE ',num2str(wavelength_sweep(l)),'NM']);
    writeline(v_pwrmtr, t);
        % writeline(v, "SENS:POW:WAVE?");
        % wavel = readline(v);

    % 3) Read Power of 
    writeline(v_pwrmtr, "READ2:POW?");
    pwr = readline(v_pwrmtr);
    pwr_save(l) = str2num(pwr);

    figure(2025);clf
    plot(wavelength_sweep,pwr_save,'Marker','*');
    xlabel('Wavelength [nm]');
    ylabel('Insertion Loss [dB]');
    ylim([min(pwr_save)-1, min(pwr_save)+1]);
    xlim([wavelength_sweep(1) wavelength_sweep(end)])
    grid minor

end

% laser.disableLaser();
L.setPower(0, false,0);
L.delete();

%writeline(v_lsr, 'DISABLE');

path= "Z:\2025\NFT WDM DFG Olaf\lambda_vs_power";

dt   = datetime('now','Format','yyyyMMdd_HHmmss');
filename = fullfile(path, "loop_5_7_"+num2str(wavelength_sweep(1)) +"nm_to_"+ num2str(wavelength_sweep(end))+ "nm_" + string(dt) + ".mat");

save(filename, "pwr_save","wavelength_sweep");

disp("Saved to: " + filename);