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PhotonForge

dispersion_from_beta2

dispersion_from_beta2(
    reference_frequency: Annotated[float, minimum=0, units='Hz'],
    beta2: Annotated[float, units='s²/μm'] = 0.0,
    beta3: Annotated[float, units='s³/μm'] = 0.0,
) -> tuple[float, float]

Convert β2\beta_2, β3\beta_3 to PhotonForge’s D and S.

PhotonForge states dispersion as D and its slope S, related to the Taylor coefficients by β2=−λ0D/ω0\beta_2 = -\lambda_0 D/\omega_0 and β3=(λ0/ω0)2(S+2D/λ0)\beta_3 = (\lambda_0/\omega_0)^2 (S + 2D/\lambda_0).

Args

  • reference_frequency: Frequency at which the coefficients apply.
  • beta2: Group velocity dispersion.
  • beta3: Third-order dispersion.

Returns

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