Gaussian Beam Spot Size and Rayleigh Range Python Script Generator

import math

# Inputs
wavelength_m = 1064 * 1e-9
m2 = 1.3
focal_m = 160 * 1e-3
beam_d_m = 8 * 1e-3
power_w = 50
rep_khz = 100

# Input beam radius (1/e^2) at the lens
w_in = beam_d_m / 2.0

# Focused waist radius (far-field approximation, lens at the beam waist)
w0 = m2 * wavelength_m * focal_m / (math.pi * w_in)

# Rayleigh range and depth of focus (2 x Rayleigh range)
z_r = math.pi * w0 ** 2 / (m2 * wavelength_m)
dof = 2.0 * z_r

# Far-field half-angle divergence in the focused beam
theta = m2 * wavelength_m / (math.pi * w0)

# Peak intensity of a CW Gaussian beam: 2P / (pi w0^2)
peak_intensity = 2.0 * power_w / (math.pi * w0 ** 2)

print('Focused spot diameter (1/e^2): %.1f um' % (2 * w0 * 1e6))
print('Rayleigh range: %.2f mm' % (z_r * 1e3))
print('Depth of focus (2 x zR): %.2f mm' % (dof * 1e3))
print('Divergence half-angle: %.2f mrad' % (theta * 1e3))
print('Peak intensity (CW): %.3e W/cm^2' % (peak_intensity / 1e4))

if rep_khz > 0:
    pulse_energy_j = power_w / (rep_khz * 1e3)
    fluence_j_cm2 = 2.0 * pulse_energy_j / (math.pi * w0 ** 2) / 1e4
    print('Pulse energy: %.1f uJ' % (pulse_energy_j * 1e6))
    print('Peak fluence per pulse: %.2f J/cm^2' % fluence_j_cm2)