diff --git a/src/scgenerator/__init__.py b/src/scgenerator/__init__.py
index 4a9a18d..f53314d 100644
--- a/src/scgenerator/__init__.py
+++ b/src/scgenerator/__init__.py
@@ -1,15 +1,16 @@
+from . import initialize, io, math, utils
 from .initialize import (
-    ParamSequence,
-    RecoveryParamSequence,
+    Config,
     ContinuationParamSequence,
     Params,
-    Config,
+    ParamSequence,
+    RecoveryParamSequence,
 )
-from .io import Paths, load_toml, load_params
+from .io import Paths, load_params, load_toml
 from .math import abs2, argclosest, span
 from .physics import fiber, materials, pulse, simulate, units
 from .physics.simulate import RK4IP, new_simulation, resume_simulations
-from .plotting import mean_values_plot, single_position_plot, propagation_plot, plot_spectrogram
+from .physics.units import PlotRange
+from .plotting import mean_values_plot, plot_spectrogram, propagation_plot, single_position_plot
 from .spectra import Pulse, Spectrum
-from .utils.parameter import BareParams, BareConfig
-from . import utils, io, initialize, math
+from .utils.parameter import BareConfig, BareParams
diff --git a/src/scgenerator/defaults.py b/src/scgenerator/defaults.py
index 5a6097e..c568efd 100644
--- a/src/scgenerator/defaults.py
+++ b/src/scgenerator/defaults.py
@@ -8,6 +8,7 @@ default_parameters = dict(
     fit_parameters=(0.08, 200e-9),
     model="custom",
     length=1,
+    n2=2.2e-20,
     capillary_resonance_strengths=[],
     capillary_nested=0,
     gas_name="vacuum",
diff --git a/src/scgenerator/initialize.py b/src/scgenerator/initialize.py
index 1d61d26..1376500 100644
--- a/src/scgenerator/initialize.py
+++ b/src/scgenerator/initialize.py
@@ -97,8 +97,16 @@ class Params(BareParams):
         )
 
         temp_gamma = None
-        if self.effective_mode_diameter is not None:
-            self.A_eff = (self.effective_mode_diameter / 2) ** 2 * pi
+        if self.A_eff_file is not None:
+            self.A_eff_arr = fiber.compute_custom_A_eff(self)
+        elif self.A_eff is not None:
+            self.A_eff_arr = np.ones(self.t_num) * self.A_eff
+        elif self.effective_mode_diameter is not None:
+            self.A_eff_arr = np.ones(self.t_num) * (self.effective_mode_diameter / 2) ** 2 * pi
+        else:
+            self.A_eff_arr = np.ones(self.t_num) * self.n2 * self.w0 / (299792458.0 * self.gamma)
+        self.A_eff = self.A_eff_arr[0]
+
         if self.beta is not None:
             self.beta = np.array(self.beta)
             self.dynamic_dispersion = False
@@ -112,8 +120,11 @@ class Params(BareParams):
                 temp_gamma = temp_gamma(0)
 
         if self.gamma is None:
-            self.gamma = temp_gamma
+            self.gamma_arr = temp_gamma
+            self.gamma = temp_gamma[0]
             logger.info(f"using computed \u0263 = {self.gamma:.2e} W/m\u00B2")
+        else:
+            self.gamma_arr = np.ones(self.t_num) * self.gamma
 
         # Raman response
         if "raman" in self.behaviors:
@@ -155,14 +166,15 @@ class Config(BareConfig):
         self.simulation_consistency()
 
     def fiber_consistency(self):
-        if self.contains("beta"):
-            if not (self.contains("A_eff") or self.contains("effective_mode_diameter")):
-                self.get("gamma", specified_parameters=["beta"])
-            self.setdefault("model", "custom")
 
-        elif self.contains("dispersion_file"):
-            if not (self.contains("A_eff") or self.contains("effective_mode_diameter")):
-                self.get("gamma", specified_parameters=["dispersion_file"])
+        if self.contains("dispersion_file") or self.contains("beta"):
+            if not (
+                self.contains("A_eff")
+                or self.contains("A_eff_file")
+                or self.contains("effective_mode_diameter")
+            ):
+                self.get("gamma", specified_parameters=["custom fiber model"])
+                self.get("n2", specified_parameters=["custom fiber model"])
             self.setdefault("model", "custom")
 
         else:
diff --git a/src/scgenerator/physics/fiber.py b/src/scgenerator/physics/fiber.py
index 995cf92..7e2384f 100644
--- a/src/scgenerator/physics/fiber.py
+++ b/src/scgenerator/physics/fiber.py
@@ -1,4 +1,4 @@
-from typing import Any, Dict, Iterable, List, Literal, Optional, Tuple, Union
+from typing import Any, Dict, Iterable, List, Literal, Optional, Tuple, Union, TypeVar
 
 import numpy as np
 from numpy.ma import core
@@ -18,7 +18,9 @@ from . import materials as mat
 from . import units
 from .units import c, pi
 
+
 pipi = 2 * pi
+T = TypeVar("T")
 
 
 def lambda_for_dispersion(left: float, right: float) -> np.ndarray:
@@ -102,6 +104,14 @@ def D_to_beta2(D, λ):
     return -(λ ** 2) / (pipi * c) * D
 
 
+def A_to_C(A: np.ndarray, A_eff_arr: np.ndarray) -> np.ndarray:
+    return (A_eff_arr / A_eff_arr[0]) ** (-1 / 4) * A
+
+
+def C_to_A(C: np.ndarray, A_eff_arr: np.ndarray) -> np.ndarray:
+    return (A_eff_arr / A_eff_arr[0]) ** (1 / 4) * C
+
+
 def plasma_dispersion(lambda_, number_density, simple=False):
     """computes dispersion (beta2) for constant plasma
 
@@ -559,8 +569,12 @@ def dynamic_HCPCF_dispersion(
     return beta2_func, gamma_func
 
 
-def gamma_parameter(n2, w0, A_eff):
-    return n2 * w0 / (A_eff * c)
+def gamma_parameter(n2: float, w0: float, A_eff: T) -> T:
+    if isinstance(A_eff, np.ndarray):
+        A_eff_term = np.sqrt(A_eff * A_eff[0])
+    else:
+        A_eff_term = A_eff
+    return n2 * w0 / (A_eff_term * c)
 
 
 @np_cache
@@ -656,6 +670,15 @@ def PCF_dispersion(lambda_, pitch, ratio_d, w0=None, n2=None, A_eff=None):
         return beta2, gamma
 
 
+def compute_custom_A_eff(params: BareParams) -> np.ndarray:
+    data = np.load(params.A_eff_file)
+    A_eff = data["A_eff"]
+    wl = data["wavelength"]
+    return interp1d(
+        wl, A_eff, fill_value=(A_eff[wl.argmin()], A_eff[wl.argmax()]), bounds_error=False
+    )(params.l)
+
+
 def compute_loss(params: BareParams) -> Optional[np.ndarray]:
     if params.loss_file is not None:
         loss_data = np.load(params.loss_file)
@@ -671,7 +694,7 @@ def compute_loss(params: BareParams) -> Optional[np.ndarray]:
     return None
 
 
-def compute_dispersion(params: BareParams):
+def compute_dispersion(params: BareParams) -> tuple[np.ndarray, np.ndarray, tuple[float, float]]:
     """dispatch function depending on what type of fiber is used
 
     Parameters
@@ -762,12 +785,14 @@ def compute_dispersion(params: BareParams):
     )
 
     if gamma is None:
-        if params.A_eff is not None:
-            gamma = gamma_parameter(params.n2, params.w0, params.A_eff)
+        if params.A_eff_arr is not None:
+            gamma_arr = gamma_parameter(params.n2, params.w0, params.A_eff_arr)
         else:
-            gamma = 0
+            gamma_arr = np.zeros(params.t_num)
+    else:
+        gamma_arr = np.ones(params.t_num) * gamma
 
-    return beta2_coef, gamma, interp_range
+    return beta2_coef, gamma_arr, interp_range
 
 
 @np_cache
@@ -954,7 +979,7 @@ def create_non_linear_op(behaviors, w_c, w0, gamma, raman_type="stolen", f_r=0,
 
     ss_part = w_c / w0 if "ss" in behaviors else 0
 
-    if isinstance(gamma, (float, int)):
+    if isinstance(gamma, (float, int, np.ndarray)):
 
         def N_func(spectrum: np.ndarray, r=0) -> np.ndarray:
             field = ifft(spectrum)
diff --git a/src/scgenerator/physics/pulse.py b/src/scgenerator/physics/pulse.py
index 8106282..8f1299c 100644
--- a/src/scgenerator/physics/pulse.py
+++ b/src/scgenerator/physics/pulse.py
@@ -14,6 +14,7 @@ import os
 from pathlib import Path
 from typing import Literal, Tuple, TypeVar
 from collections import namedtuple
+from dataclasses import dataclass, astuple
 
 import matplotlib.pyplot as plt
 import numpy as np
@@ -49,10 +50,54 @@ P0T0_to_E0_fac = dict(
 )
 """relates the total energy (amplitue^2) to the t0 parameter of the amplitude and the peak intensity (peak_amplitude^2)"""
 
-PulseProperties = namedtuple(
-    "PulseProperties",
-    "quality mean_coherence fwhm_noise mean_fwhm peak_rin energy_rin timing_jitter",
-)
+
+@dataclass
+class PulseProperties:
+    quality: float
+    mean_coherence: float
+    fwhm_noise: float
+    mean_fwhm: float
+    peak_rin: float
+    energy_rin: float
+    timing_jitter: float
+
+    @classmethod
+    def header(cls, delimiter: str = ",", quotechar: str = "") -> str:
+        return delimiter.join(
+            quotechar + f + quotechar
+            for f in [
+                "quality",
+                "mean_coherence",
+                "fwhm_noise",
+                "mean_fwhm",
+                "peak_rin",
+                "energy_rin",
+                "timing_jitter",
+            ]
+        )
+
+    @classmethod
+    def save_all(
+        cls,
+        destination: os.PathLike,
+        *props: "PulseProperties",
+        delimiter: str = ",",
+        quotechar: str = "",
+    ):
+        out = np.zeros((len(props), 7))
+        for i, p in enumerate(props):
+            out[i] = astuple(p)
+        np.savetxt(
+            destination,
+            out,
+            header=cls.header(delimiter=delimiter, quotechar=quotechar),
+            delimiter=delimiter,
+        )
+
+    @classmethod
+    def load(cls, path: os.PathLike, delimiter: str = ",") -> list["PulseProperties"]:
+        arr = np.loadtxt(path, delimiter=delimiter)
+        return [cls(*a) for a in arr]
 
 
 def initial_field(t, shape, t0, peak_power):
@@ -954,6 +999,25 @@ def measure_properties(spectra, t, compress=True, return_limits=False, debug="")
         return pp
 
 
+def rin_curve(spectra: np.ndarray) -> np.ndarray:
+    """computes the rin curve, i.e. the rin at every single point
+
+    Parameters
+    ----------
+    spectra : np.ndarray, shape (n, nt)
+        a collection of n spectra from which to compute the RIN
+
+    Returns
+    -------
+    rin_curve : np.ndarray
+        RIN curve
+    """
+    spec2 = abs2(spectra)
+    # return np.std(spec, axis=0) / np.mean(spec, axis=0)
+    m = np.mean(spec2, axis=0)
+    return np.sqrt(np.mean((spec2 - m) ** 2)) / m
+
+
 def measure_field(t: np.ndarray, field: np.ndarray) -> Tuple[float, float, float]:
     """returns fwhm, peak_power, energy"""
     intensity = abs2(field)
diff --git a/src/scgenerator/physics/simulate.py b/src/scgenerator/physics/simulate.py
index 5c2837d..9bf8175 100644
--- a/src/scgenerator/physics/simulate.py
+++ b/src/scgenerator/physics/simulate.py
@@ -13,6 +13,7 @@ from ..errors import IncompleteDataFolderError
 from ..logger import get_logger
 from . import pulse
 from .fiber import create_non_linear_op, fast_dispersion_op
+from scgenerator.physics import fiber
 
 try:
     import ray
@@ -72,7 +73,8 @@ class RK4IP:
         self.z_targets = params.z_targets
         self.z_final = params.length
         self.beta = params.beta_func if params.beta_func is not None else params.beta
-        self.gamma = params.gamma_func if params.gamma_func is not None else params.gamma
+        self.gamma = params.gamma_func if params.gamma_func is not None else params.gamma_arr
+        self.C_to_A_factor = (params.A_eff_arr / params.A_eff_arr[0]) ** (-1 / 4)
         self.behaviors = params.behaviors
         self.raman_type = params.raman_type
         self.hr_w = params.hr_w
@@ -135,7 +137,7 @@ class RK4IP:
         self.z = self.z_targets.pop(0)
 
         # Setup initial values for every physical quantity that we want to track
-        self.current_spectrum = self.spec_0.copy()
+        self.current_spectrum = self.spec_0.copy() / self.C_to_A_factor
         self.stored_spectra = self.starting_num * [None] + [self.current_spectrum.copy()]
         self.cons_qty = [
             self.conserved_quantity_func(self.current_spectrum, 0),
@@ -160,7 +162,7 @@ class RK4IP:
         num : int
             index of the z postition
         """
-        self._save_data(self.current_spectrum, f"spectrum_{num}")
+        self._save_data(self.C_to_A_factor * self.current_spectrum, f"spectrum_{num}")
         self._save_data(self.cons_qty, f"cons_qty")
         self.step_saved()
 
diff --git a/src/scgenerator/physics/units.py b/src/scgenerator/physics/units.py
index 6e040e2..d49de0e 100644
--- a/src/scgenerator/physics/units.py
+++ b/src/scgenerator/physics/units.py
@@ -2,14 +2,10 @@
 # For example, nm(X) means "I give the number X in nm, figure out the ang. freq."
 # to be used especially when giving plotting ranges : (400, 1400, nm), (-4, 8, ps), ...
 
-import re
-from threading import settrace
 from typing import Callable, TypeVar, Union
 from dataclasses import dataclass
-from matplotlib import pyplot as plt
 
-from numpy.lib.arraysetops import isin
-from ..utils.parameter import Parameter, type_checker
+from ..utils.parameter import Parameter, boolean, type_checker
 import numpy as np
 from numpy import pi
 
@@ -190,6 +186,7 @@ class PlotRange:
     left: float = Parameter(type_checker(int, float))
     right: float = Parameter(type_checker(int, float))
     unit: Callable[[float], float] = Parameter(is_unit, converter=get_unit)
+    conserved_quantity: bool = Parameter(boolean, default=True)
 
     def __str__(self):
         return f"{self.left:.1f}-{self.right:.1f} {self.unit.__name__}"
diff --git a/src/scgenerator/plotting.py b/src/scgenerator/plotting.py
index 3d08f76..ce4a5a2 100644
--- a/src/scgenerator/plotting.py
+++ b/src/scgenerator/plotting.py
@@ -535,7 +535,7 @@ def transform_mean_values(
         if log is not True and isinstance(log, (int, float, np.integer, np.floating)):
             ref = log
         else:
-            ref = mean_values.max()
+            ref = float(mean_values.max())
         values = apply_log(values, ref)
         mean_values = apply_log(mean_values, ref)
     return new_axis, mean_values, values
@@ -875,7 +875,7 @@ def uniform_axis(
         new_axis = tmp_axis
         values = values[:, ind]
     else:
-        if plt_range.unit.type == "WL":
+        if plt_range.unit.type == "WL" and plt_range.conserved_quantity:
             values[:, ind] = np.apply_along_axis(units.to_WL, 1, values[:, ind], tmp_axis)
         new_axis = np.linspace(tmp_axis.min(), tmp_axis.max(), len(tmp_axis))
         values = np.array([interp1d(tmp_axis, v[ind])(new_axis) for v in values])
diff --git a/src/scgenerator/utils/parameter.py b/src/scgenerator/utils/parameter.py
index b852a78..dda2cf3 100644
--- a/src/scgenerator/utils/parameter.py
+++ b/src/scgenerator/utils/parameter.py
@@ -252,6 +252,7 @@ valid_variable = {
     "dispersion_file",
     "field_file",
     "loss_file",
+    "A_eff_file",
     "beta",
     "gamma",
     "pitch",
@@ -325,6 +326,7 @@ class BareParams:
     loss_file: str = Parameter(string)
     effective_mode_diameter: float = Parameter(positive(float, int))
     A_eff: float = Parameter(non_negative(float, int))
+    A_eff_file: str = Parameter(string)
     pitch: float = Parameter(in_range_excl(0, 1e-3))
     pitch_ratio: float = Parameter(in_range_excl(0, 1))
     core_radius: float = Parameter(in_range_excl(0, 1e-3))
@@ -386,6 +388,8 @@ class BareParams:
     field_0: np.ndarray = Parameter(type_checker(np.ndarray))
     spec_0: np.ndarray = Parameter(type_checker(np.ndarray))
     alpha: np.ndarray = Parameter(type_checker(np.ndarray))
+    gamma_arr: np.ndarray = Parameter(type_checker(np.ndarray))
+    A_eff_arr: np.ndarray = Parameter(type_checker(np.ndarray))
     w: np.ndarray = Parameter(type_checker(np.ndarray))
     l: np.ndarray = Parameter(type_checker(np.ndarray))
     w_c: np.ndarray = Parameter(type_checker(np.ndarray))
@@ -434,6 +438,8 @@ class BareParams:
             "z_targets",
             "l",
             "alpha",
+            "gamma_arr",
+            "A_eff_arr",
         ]
         types = (np.ndarray, float, int, str, list, tuple, dict)
         out = {}