finesse.model.Model.phase_config

Model.phase_config(zero_k00=True, zero_tem00_gouy=True)[source]

Coupling coefficient and Gouy phase scaling:

  • phase_level 3 == zero_k00=True, zero_tem00_gouy=True

  • phase_level 2 == zero_k00=False, zero_tem00_gouy=True

  • phase_level 1 == zero_k00=True, zero_tem00_gouy=False

  • phase_level 0 == zero_k00=False, zero_tem00_gouy=False

This can be used to change the computation of light field phases in the Hermite-Gauss mode. In general, with higher order modes spaces are not resonant any more for the TEM00 mode because of the Gouy phase. Furthermore, the coupling coefficients k_nmnm contribute to the phase when there is a mode mismatch. For correct analysis these effects have to be taken into account. On the other hand, these extra phase offsets make it very difficult to set a resonance condition or operating point intuitively. In most cases another phase offset can be added to all modes so that the phase of the TEM00 becomes zero. With this method these phase offsets can be set for the propagation through free space, for the coupling coefficients, or both. Regardless of setting, the phases for all higher modes are changed accordingly such that the relative phases remain correct.

Parameters
zero_k00bool, optional

Scale phase for k0000 (TEM00 to TEM00) coupling coefficients to 0. Defaults to True.

zero_tem00_gouybool, optional

Ensure that all Gouy phases for TEM00 are 0. Defaults to True.