finesse.gaussian.BeamParam.w

property BeamParam.w

The radius of the beam, \(w\), in metres.

Computed as,

\[w = |q|\,\sqrt{\frac{\lambda}{n_r \pi z_R}},\]

where \(q\) is the complex beam parameter (given by BeamParam.q), \(\lambda\) is the beam wavelength (given by BeamParam.wavelength), \(n_r\) is the refractive index of the associated medium (given by BeamParam.nr) and \(z_R\) is the Rayleigh range (given by BeamParam.zr, or BeamParam.imag).

Hint

Use BeamParam.beamsize() to compute the beam size as a function of any of the above dependent arguments.

Getter:

Returns the radius, often denoted as “beam-size”, of the beam. Read-only.