comnum.Edfa

class comnum.Edfa(*, gain_db=Ellipsis, nf_db=Ellipsis, fc_hz=Ellipsis)

An ideal erbium-doped fibre amplifier: flat gain and white ASE.

The spontaneous-emission factor is n_sp = (G·NF - 1)/(2(G - 1)) and the ASE adds complex Gaussian noise of variance (G - 1) n_sp h f_c f_s per sample at the sampling rate f_s (OptiCommPy edfa). The defaults are those of OptiCommPy.

Parameters:

• gain_db (float) – gain (dB, positive).

• nf_db (float) – noise figure (dB, at least 3 dB).

• fc_hz (float) – carrier frequency (Hz).

apply(x, fs, rng)

Amplify a field and add the ASE.

Parameters:

• x (array_like) – the field (√W).

• fs (float) – sampling rate (Hz).

• rng (Rng) – the generator of the ASE.

Returns:

the amplified field (complex128).

Return type:

numpy.ndarray

Raises:

ValueError – for a gain that is not positive or a noise figure below 3 dB.

noise_variance(fs)

Variance of the ASE per sample.

Parameters:

fs (float) – sampling rate (Hz).

Returns:

the variance E|w|² (W).

Return type:

float

ase_psd

ASE power spectral density (G - 1) n_sp h f_c (W/Hz).

Type:

float

fc_hz

Carrier frequency (Hz) (read and write).

Type:

float

gain_db

Gain (dB) (read and write).

Type:

float

n_sp

Spontaneous-emission factor n_sp.

Type:

float

nf_db

Noise figure (dB) (read and write).

Type:

float