#
# Analyze voltage sweep
#

L = 500e-6;                          # set the length of the modulator arm
neff=pinch(getsweepdata("voltage","neff"));
dneff = real(neff - neff(1));         # relative change in index
la0 = getnamed("MODE","wavelength");  # central wavelength
rel_phase = 2*pi*dneff/la0*L;         # phase change
alpha_dB_cm = -0.2*log10(exp(1))*(-2*pi*imag(neff)/la0);

ref_ds = getresult('gate np density','charge');
V = ref_ds.V_gate;

plot(V,rel_phase, "Voltage (V)", "Relative phase (rad.)");
plot(V,alpha_dB_cm, "Voltage (V)", "loss (dB/cm)");