get_layout_params_1xM_demux_um

awg_designer.all.get_layout_params_1xM_demux_um(aperture_in, aperture_arms, aperture_out, waveguide_template, output_spacing, M, center_wavelength, channel_spacing, FSR=None, grating_period=None, N_arms=None, alpha_factor=1.6, use_same_radius_for_input=True, verbose=False)

Calculate the layout parameters for building a 1xM AWG (1 input, M outputs), with channels equidistant in wavelength.

Parameters:

aperture_in, aperture_arms, aperture_out: PCells: Aperture component for input, output and arms.
waveguide_template: PCell template: Waveguide template for the delay lines.
output_spacing: float: Minimum spacing (center to center) of output apertures. Increasing this value means less cross-talk but also more power lost between two channels.
M: integer: Number of output channels.
center_wavelength: float: Center frequency of the filter [um].
channel_spacing: float: Channel spacing [um].
FSR: float (default=None): Free spectral range [um]. if None, use M * channel_spacing.
grating_period: float or None (default=None): Period of the grating apertures. If None, it uses a value as small as possible (the width of the aperture + 0.2 um).
N_arms: integer or None (default=None): Number of waveguide arms. If None, calculate automatically. Automatic calculation is done based on the spreading angle of the output aperture and R_grating.
alpha_factor: float (default=1.6): Scaling of the divergence angle (NA) of input and output. The actual spreading angle used equals divergence angle * alpha_factor.
use_same_radius_for_input (default=True): When True, use the same radius for the input star coupler as for the output (i.e., R_input=R_grating)
verbose: boolean (default=False): When True, print the intermediate design parameters (useful for debugging)

Returns:

A dictionary of layout parameters, including delay_length, N_arms,
R_grating, R_input, angles_arms_in, angles_arms_out, angles_out

delay_length:
Delay line length to give the specified FSR. It is optimized to be centered at center_frequency, so the actual FSR may be slightly different. See also delay_length_from_FSR().
N_arms (only calculated if None was specified):
Calculate the number of arms that fit into the spreading angle of the output aperture. Depends on: R_grating, grating_period, and divergence angle of aperture_out. If manually specified, this may increase the R_grating.
R_grating:
Radius of the grating. This is determined in such a way that the first order diffraction of the grating falls outside of the range of the output apertures. See also get_R_grating(). Depends on: FSR / channel_spacing, grating_period, output_spacing, and slab material properties.
R_input:
When use_same_radius_for_input is True, equals R_grating. Otherwise, based on the divergence angle of the input aperture.
angles_arms_in, angles_arms_out:
Angles at which to position the grating apertures for the input/output star coupler, respectively.
angles_out:
Angles at which to position the output apertures. See also get_angles_out().