gbeampro 1.0.1

Python package for designing gaussian laser beam propagation and transformation.

gbeampro

gbeampro is a small Python package for simulating Gaussian (TEM₀₀) laser beam propagation and transformations using the ABCD matrix method (q-parameter formalism).

Installation

pip install gbeampro

Quick Start

from gbeampro import beambase

# Define a beam: 1064 nm, w=1 mm, flat wavefront
beam = beambase.GaussBeam(wl_um=1.064, n=1.0, w_mm=1.0)

# Propagate 100 mm, focus with f=50 mm lens, propagate into crystal (n=1.5)
beam.propagate(50).thinlens(50).interface(1.5).propagate(10)

# Find beam waists
beam.search_BeamWaists()

API Reference

GaussBeam(wl_um, n, z_mm, R_mm, w_mm, label)

Fundamental Gaussian beam object.

Parameter	Description	Unit
wl_um	Wavelength	µm
n	Refractive index of medium	—
z_mm	z-coordinate of wavefront	mm
R_mm	Wavefront curvature radius	mm
w_mm	Beam radius (1/e² intensity half-width)	mm
label	Label string	—

Key attributes: .q (complex q-parameter), .theta (divergence half-angle in rad).

Transformation Methods

All methods mutate the beam in-place and return self, enabling method chaining.

Method	Description
propagate(d_total, dz=0.01)	Free-space propagation over distance d_total (mm), recorded at steps of dz
thinlens(f)	Thin lens with effective focal length f (mm)
interface(n2)	Refraction at a flat dielectric interface into medium with index n2
interface_curved(n2, r)	Refraction at a curved dielectric interface; r > 0 convex, r < 0 concave (mm)
curved_mirror_tan(r, theta_deg)	Reflection from a curved mirror, tangential (in-plane) component
curved_mirror_sag(r, theta_deg)	Reflection from a curved mirror, sagittal (out-of-plane) component

Analysis Methods

Method	Description
search_BeamWaists(out=False)	Locate beam waists (sign change of R). Prints results; returns (n, z, w) arrays if out=True

Plot Methods

Method	Description
plot_w(ax)	Beam radius w vs z
plot_R(ax)	Wavefront curvature radius R vs z
plot_n(ax)	Refractive index n vs z
plot_theta(ax)	Divergence half-angle θ vs z

Trajectory

Every transformation appends to beam.traj, a dict of lists:

Key	Description
z_mm	z-coordinate (mm)
n	Refractive index
R_mm	Wavefront curvature radius (mm)
w_mm	Beam radius (mm)
q	Complex q-parameter
theta_rad	Divergence half-angle (rad)

Examples

• Beam focusing into a slab of crystal

License

See LICENSE.