treams.sw.periodic_to_cw

treams.sw.periodic_to_cw(kz, m, pol, l, mu, qol, k, area, helicity=True)

Convert periodic spherical wave to plane wave.

Returns the coefficient for the basis change in a periodic arrangement of spherical modes to plane waves. For multiple positions only diagonal values (with respect to the position) are returned. A correct phase factor is still necessary for the full result.

The polarization values 0 and 1 refer to negative and positive helicity waves or, if helicity == False, to TE and TM parity.

Parameters:

• kz (float, array_like) – Z component of destination mode wave vector

• m (int, array_like) – Order or the destination mode

• pol (int, array_like) – Polarization of the destination mode

• l (int, array_like) – Degree of the source mode

• mu (int, array_like) – Order of the source mode

• qol (int, array_like) – Polarization of the source mode

• k (float or complex, array_like) – Wave number

• area (float, array_like) – Unit cell area

• helicity (bool, optional) – If true, helicity basis is assumed, else parity basis. Defaults to True.

Returns:

complex