It is recommended to import scgenerator in the following manner :
import scgenerator as sc
How to run a set of simulations
create a config file
run sc.parallel_simulations(config_file) or sc.simulate(config_file)
How to analyse a simulation
load data with the load_sim_data method spectra, params = load_sim_data("varyTechNoise100kW_sim_data") to plot plot_results_2D(spectra[0], (600, 1450, nm), params)
Configuration
You can load parameters by simpling passing the path to a toml file to the appropriate simulation function. Each possible key of this dictionary is described below. Every value must be given in standard SI units (m, s, W, J, ...)
The configuration file can have a name parameter at the root and must otherwise contain the following sections with the specified parameters
note : internally, another structure with a flattened dictionary is used
Fiber parameters
If you already know the Taylor coefficients corresponding to the expansion of the beta2 profile, you can specify them and skip to "Other fiber parameters":
beta: list-like list of Taylor coefficients for the beta_2 function
else, you can choose a mathematical fiber model
model: str {"pcf", "marcatili", "marcatili_adjusted", "hasan"}
PCF : solid core silica photonic crystal fiber, as modeled in Saitoh, Kunimasa, and Masanori Koshiba. "Empirical relations for simple design of photonic crystal fibers." Optics express 13.1 (2005): 267-274.
marcatili : Marcatili model of a capillary fiber : Marcatili, Enrique AJ, and R. A. Schmeltzer. "Hollow metallic and dielectric waveguides for long distance optical transmission and lasers." Bell System Technical Journal 43.4 (1964): 1783-1809.
marcatili_adjusted : Marcatili model of a capillary fiber with adjusted effective radius in the longer wavelength : Köttig, F., et al. "Novel mid-infrared dispersive wave generation in gas-filled PCF by transient ionization-driven changes in dispersion." arXiv preprint arXiv:1701.04843 (2017).
hasan : Hasan model of hollow core anti-resonance fibers : Hasan, Md Imran, Nail Akhmediev, and Wonkeun Chang. "Empirical formulae for dispersion and effective mode area in hollow-core antiresonant fibers." Journal of Lightwave Technology 36.18 (2018): 4060-4065.
and specify the parameters it needs
pcf :
pitch: float distance between air holes in m pitch_ratio: float 0.2 < pitch_ratio < 0.8 ratio hole diameter/pich
marcatili, marcatili_adjusted, hasan :
core_radius: float radius of the hollow core in m
marcatili, marcatili_adjusted :
he_mode: list, shape (2, ), optional mode of propagation. default is (1, 1), which is the fundamental mode
marcatili_adjusted :
fit_parameters: list, shape (2, ), optional parameters for the effective radius correction. Defaults are (s, h) = (0.08, 200e-9) as in the referenced paper.
hasan :
capillary_num : int number of capillaries
capillary_outer_d : float, optional if g is specified outer diameter of the capillaries
capillary_thickness : float thickness of the capillary walls
capillary_spacing : float, optional if d is specified spacing between the capillary
capillray_resonance_strengths : list, optional list of resonance strengths. Default is []
capillary_nested : int, optional how many nested capillaries. Default is 0
Other fiber parameters :
gamma: float, optional unless beta is directly provided nonlinear parameter in m^2 / W. Will overwrite any computed gamma parameter.
length: float, optional length of the fiber in m. default : 1
fiber_id : int in case multiple fibers are chained together, indicates the index of this particular fiber, default : 0
input_transmission : float number between 0 and 1 indicating how much light enters the fiber, default : 1
Gas parameters
this section is completely optional and ignored if the fiber model is "pcf"
gas_name: str name of the gas. default : "vacuum"
pressure: float pressure of the gas in the fiber. default : 1e5
temperature: float temperature of the gas in the fiber. default : 300
plasma_density: float constant plasma density (in m^-3). default : 0
Pulse parameters:
Mandatory
wavelength: float pump wavelength in m
To specify the initial pulse shape, either use one of 2 in (power, energy) together with one of 2 in (width, t0), or use soliton_num together with one of 4 in (power, energy, width, t0)
power: float peak power in W
energy: float total pulse energy in J
width: float full width half maximum of the pulse in s. Will be converted to appropriate t0 depending on pulse shape
t0: float pulse width parameter
solition_num: float soliton number
optional
quantum_noise: bool whether or not one-photon-per-mode quantum noise is activated. default : False
intensity_noise: float relative intensity noise
shape: str {"gaussian", "sech"} shape of the pulse. default : gaussian
Simulation parameters
2 of 3
dt: float resolution of the temporal grid in s
t_num: int number of temporal grid points
time_window: float total length of the temporal grid in s
optional
behaviors: list of str {"spm", "raman", "ss"} spm is self-phase modulation raman is raman effect ss is self-steepening default : ["spm", "ss"]
raman_type: str {"measured", "stolen", "agrawal"} type of Raman effect. Default is "agrawal".
ideal_gas: bool if True, use the ideal gas law. Otherwise, use van der Waals equation. default : False
z_num : int number of spatial grid points along the fiber. default : 128
frep: float repetition rate in Hz. Only useful to convert units. default : 80e6
tolerated_error: float relative tolerated step-to-step error. default : 1e-11
step_size: float if given, sets a constant step size rather than adapting it.
parallel: bool whether to run simulations in parallel with the available ressources. default : false
repeat: int how many simulations to run per parameter set. default : 1
lower_wavelength_interp_limit: float dispersion coefficients are computed over a certain wavelength range. This parameter sets the lowest end of this range. If the set value is lower than the lower end of the wavelength window, it is raised up to that point. default : 0
upper_wavelength_interp_limit: float dispersion coefficients are computed over a certain wavelength range. This parameter sets the lowest end of this range. If the set value is higher than the higher end of the wavelength window, it is lowered down to that point. default : 1900e-9