get_R_grating

awg_designer.all.get_R_grating(FSR, channel_spacing, output_spacing, grating_period, wl, slab_n_eff)

Calculates the minimal grating radius such that all channels fit in the first order diffraction of the grating.

The first order diffraction angle is calculated from the grating_period, wl and slab_n_eff.

Parameters:

FSR: float

Free spectral range [GHz].

channel_spacing: float

Channel spacing [GHz]. By dividing FSR / channel_spacing, we get the ‘effective’ number of outputs.

output_spacing: float

The spacing between the output apertures.

grating_period: float

The grating period.

wl: float

Wavelength (choose the lowest wavelength that you want to support).

slab_n_eff: float

Effective index of the slab (at wavelength ‘wl’).

Returns:

The minimum required grating radius (float).