 codex/gaussian-field-power-width.py

"""Generate gaussian-field-power-width.png in cwd (_media).

Tested with Python 3.14.4 and Matplotlib 3.10.7; NumPy/Matplotlib
dependencies are recorded in the repository pyproject.toml.
"""
import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
import numpy as np

t=np.linspace(-1.5,1.5,901)
fig,axes=plt.subplots(1,2,figsize=(7,3.2),dpi=100,layout='constrained')
for ax,exponent,half,color,title,label,width in [
    (axes[0],2*np.log(2),np.sqrt(2)/2,'#b35806','Field-envelope magnitude',r'$|A(t)|/|A(0)|$',r'$\tau_E=\sqrt{2}\,\tau_P$'),
    (axes[1],4*np.log(2),.5,'#2166ac','Optical power',r'$P(t)/P(0)$',r'FWHM $=\tau_P$'),
]:
    ax.plot(t,np.exp(-exponent*t*t),color=color,linewidth=2)
    ax.axhline(.5,color='gray',linestyle=':',linewidth=1)
    ax.vlines([-half,half],0,.5,color=color,linestyle='--',linewidth=1)
    ax.scatter([-half,half],[.5,.5],color=color,zorder=3)
    ax.set(xlim=(-1.5,1.5),ylim=(0,1.05),xlabel=r'Time / power FWHM ($t/\tau_P$)',ylabel=label,title=title)
    ax.set_xticks([-1.5,-1,-.5,0,.5,1,1.5])
    ax.text(0,.88,width,ha='center',fontsize=11,bbox={'facecolor':'white','edgecolor':'none','alpha':.85})
    ax.grid(alpha=.15)
fig.savefig('gaussian-field-power-width.png',facecolor='white',dpi=100)
plt.close(fig)