Files
oopt-gnpy/gnpy/core/parameters.py
AndreaDAmico e6a3d9ce5b Small change on Fiber parameters
Squeeze function has been replaced by asarray. Using 'get' function
instead of if condition for the dictionaries.  Frequency reference
derived from wavelength reference of 1550 nm.

Change-Id: I815ad8591c9e238f3fc9322ca0946ea469ff448f
2022-01-06 12:00:00 +01:00

241 lines
8.0 KiB
Python

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
gnpy.core.parameters
====================
This module contains all parameters to configure standard network elements.
"""
from scipy.constants import c, pi
from numpy import asarray, log10, exp
from gnpy.core.utils import db2lin, convert_length
from gnpy.core.exceptions import ParametersError
class Parameters:
def asdict(self):
class_dict = self.__class__.__dict__
instance_dict = self.__dict__
new_dict = {}
for key in class_dict:
if isinstance(class_dict[key], property):
new_dict[key] = instance_dict['_' + key]
return new_dict
class PumpParams(Parameters):
def __init__(self, power, frequency, propagation_direction):
self.power = power
self.frequency = frequency
self.propagation_direction = propagation_direction.lower()
class RamanParams(Parameters):
def __init__(self, flag=False, space_resolution=10e3, tolerance=None):
""" Simulation parameters used within the Raman Solver
:params flag: boolean for enabling/disable the evaluation of the Raman Power profile in frequency and position
:params space_resolution: spatial resolution of the evaluated Raman Power profile
:params tolerance: tuning parameter for scipy.integrate.solve_bvp solution
"""
self.flag = flag
self.space_resolution = space_resolution # [m]
self.tolerance = tolerance
class NLIParams(Parameters):
def __init__(self, method='gn_model_analytic', dispersion_tolerance=1, phase_shift_tolerance=0.1,
computed_channels=None, wdm_grid_size=None, f_cut_resolution=None, f_pump_resolution=None):
""" Simulation parameters used within the Nli Solver
:params method: formula for NLI calculation
:params dispersion_tolerance: tuning parameter for ggn model solution
:params phase_shift_tolerance: tuning parameter for ggn model solution
:params computed_channels: the NLI is evaluated for these channels and extrapolated for the others
"""
self.method = method.lower()
self.dispersion_tolerance = dispersion_tolerance
self.phase_shift_tolerance = phase_shift_tolerance
self.computed_channels = computed_channels
self.wdm_grid_size = wdm_grid_size
self.f_cut_resolution = f_cut_resolution
self.f_pump_resolution = f_pump_resolution
class SimParams(Parameters):
_shared_dict = {'nli_params': NLIParams(), 'raman_params': RamanParams()}
def __init__(self):
if type(self) == SimParams:
raise NotImplementedError('Instances of SimParams cannot be generated')
@classmethod
def set_params(cls, sim_params):
cls._shared_dict['nli_params'] = NLIParams(**sim_params.get('nli_params', {}))
cls._shared_dict['raman_params'] = RamanParams(**sim_params.get('raman_params', {}))
@classmethod
def get(cls):
self = cls.__new__(cls)
return self
@property
def nli_params(self):
return self._shared_dict['nli_params']
@property
def raman_params(self):
return self._shared_dict['raman_params']
class FiberParams(Parameters):
def __init__(self, **kwargs):
try:
self._length = convert_length(kwargs['length'], kwargs['length_units'])
# fixed attenuator for padding
self._att_in = kwargs.get('att_in', 0)
# if not defined in the network json connector loss in/out
# the None value will be updated in network.py[build_network]
# with default values from eqpt_config.json[Spans]
self._con_in = kwargs.get('con_in')
self._con_out = kwargs.get('con_out')
if 'ref_wavelength' in kwargs:
self._ref_wavelength = kwargs['ref_wavelength']
self._ref_frequency = c / self._ref_wavelength
elif 'ref_frequency' in kwargs:
self._ref_frequency = kwargs['ref_frequency']
self._ref_wavelength = c / self._ref_frequency
else:
self._ref_wavelength = 1550e-9 # conventional central C band wavelength [m]
self._ref_frequency = c / self._ref_wavelength
self._dispersion = kwargs['dispersion'] # s/m/m
self._dispersion_slope = \
kwargs.get('dispersion_slope', -2 * self._dispersion / self.ref_wavelength) # s/m/m/m
self._beta2 = -(self.ref_wavelength ** 2) * self.dispersion / (2 * pi * c) # 1/(m * Hz^2)
# Eq. (3.23) in Abramczyk, Halina. "Dispersion phenomena in optical fibers." Virtual European University
# on Lasers. Available online: http://mitr.p.lodz.pl/evu/lectures/Abramczyk3.pdf
# (accessed on 25 March 2018) (2005).
self._beta3 = ((self.dispersion_slope - (4*pi*c/self.ref_wavelength**3) * self.beta2) /
(2*pi*c/self.ref_wavelength**2)**2)
self._gamma = kwargs['gamma'] # 1/W/m
self._pmd_coef = kwargs['pmd_coef'] # s/sqrt(m)
if type(kwargs['loss_coef']) == dict:
self._loss_coef = asarray(kwargs['loss_coef']['value']) * 1e-3 # lineic loss dB/m
self._f_loss_ref = asarray(kwargs['loss_coef']['frequency']) # Hz
else:
self._loss_coef = asarray(kwargs['loss_coef']) * 1e-3 # lineic loss dB/m
self._f_loss_ref = asarray(self._ref_frequency) # Hz
self._lin_attenuation = db2lin(self.length * self.loss_coef)
self._lin_loss_exp = self.loss_coef / (10 * log10(exp(1))) # linear power exponent loss Neper/m
self._effective_length = (1 - exp(- self.lin_loss_exp * self.length)) / self.lin_loss_exp
self._asymptotic_length = 1 / self.lin_loss_exp
# raman parameters (not compulsory)
self._raman_efficiency = kwargs.get('raman_efficiency')
self._pumps_loss_coef = kwargs.get('pumps_loss_coef')
except KeyError as e:
raise ParametersError(f'Fiber configurations json must include {e}. Configuration: {kwargs}')
@property
def length(self):
return self._length
@length.setter
def length(self, length):
"""length must be in m"""
self._length = length
@property
def att_in(self):
return self._att_in
@att_in.setter
def att_in(self, att_in):
self._att_in = att_in
@property
def con_in(self):
return self._con_in
@con_in.setter
def con_in(self, con_in):
self._con_in = con_in
@property
def con_out(self):
return self._con_out
@con_out.setter
def con_out(self, con_out):
self._con_out = con_out
@property
def dispersion(self):
return self._dispersion
@property
def dispersion_slope(self):
return self._dispersion_slope
@property
def gamma(self):
return self._gamma
@property
def pmd_coef(self):
return self._pmd_coef
@property
def ref_wavelength(self):
return self._ref_wavelength
@property
def ref_frequency(self):
return self._ref_frequency
@property
def beta2(self):
return self._beta2
@property
def beta3(self):
return self._beta3
@property
def loss_coef(self):
return self._loss_coef
@property
def f_loss_ref(self):
return self._f_loss_ref
@property
def lin_loss_exp(self):
return self._lin_loss_exp
@property
def lin_attenuation(self):
return self._lin_attenuation
@property
def effective_length(self):
return self._effective_length
@property
def asymptotic_length(self):
return self._asymptotic_length
@property
def raman_efficiency(self):
return self._raman_efficiency
@property
def pumps_loss_coef(self):
return self._pumps_loss_coef
def asdict(self):
dictionary = super().asdict()
dictionary['loss_coef'] = self.loss_coef * 1e3
dictionary['length_units'] = 'm'
return dictionary