dispersion_from_beta2

photonforge.dispersion_from_beta2(reference_frequency, beta2=0, beta3=0)[source]

Convert \(\beta_2\), \(\beta_3\) to PhotonForge’s D and S.

PhotonForge states dispersion as D and its slope S, related to the Taylor coefficients by \(\beta_2 = -\lambda_0 D/\omega_0\) and \(\beta_3 = (\lambda_0/\omega_0)^2 (S + 2D/\lambda_0)\).

Parameters:

  • reference_frequency (Annotated[float, minimum=0, units='Hz']) – Frequency at which the coefficients apply.

  • beta2 (Annotated[float, units='s²/μm']) – Group velocity dispersion.

  • beta3 (Annotated[float, units='s³/μm']) – Third-order dispersion.

Returns:

Tuple (dispersion, dispersion_slope) in s/μm² and s/μm³.

Return type:

tuple[float, float]