diff --git a/src/scgenerator/const.py b/src/scgenerator/const.py
index e6ecafe..268643f 100644
--- a/src/scgenerator/const.py
+++ b/src/scgenerator/const.py
@@ -75,7 +75,6 @@ VALID_VARIABLE = {
 
 MANDATORY_PARAMETERS = [
     "name",
-    "w_c",
     "w",
     "w0",
     "spec_0",
diff --git a/src/scgenerator/evaluator.py b/src/scgenerator/evaluator.py
index 269a82a..4d669f6 100644
--- a/src/scgenerator/evaluator.py
+++ b/src/scgenerator/evaluator.py
@@ -1,6 +1,7 @@
 import itertools
 from collections import defaultdict
 from dataclasses import dataclass
+from operator import itemgetter
 from typing import Any, Callable, Optional, Union
 
 import numpy as np
@@ -26,7 +27,7 @@ class Rule:
         if priorities is None:
             priorities = [0] * len(targets)
         elif isinstance(priorities, (int, float, np.integer, np.floating)):
-            priorities = [priorities]
+            priorities = [priorities] * len(targets)
         self.targets = dict(zip(targets, priorities))
         if args is None:
             args = get_arg_names(func)
@@ -99,14 +100,20 @@ class Evaluator:
     defaults: dict[str, Any] = {}
 
     @classmethod
-    def default(cls) -> "Evaluator":
+    def default(cls, full_field: bool = False) -> "Evaluator":
         evaluator = cls()
-        evaluator.append(*default_rules)
+        logger = get_logger(__name__)
+        if full_field:
+            logger.debug("Full field simulation")
+            evaluator.append(*full_field_rules)
+        else:
+            logger.debug("Envelope simulation")
+            evaluator.append(*envelope_rules)
         return evaluator
 
     @classmethod
     def evaluate_default(cls, params: dict[str, Any], check_only=False) -> dict[str, Any]:
-        evaluator = cls.default()
+        evaluator = cls.default(params.get("full_field", False))
         evaluator.set(**params)
         for target in MANDATORY_PARAMETERS:
             evaluator.compute(target, check_only=check_only)
@@ -238,6 +245,8 @@ class Evaluator:
                     )
                     self.__failed_rules[target].append(rule)
                     continue
+                except Exception as e:
+                    raise type(e)(f"error while evaluating {target!r}")
             else:
                 default = self.defaults.get(target)
                 if default is None:
@@ -282,16 +291,19 @@ class Evaluator:
 default_rules: list[Rule] = [
     # Grid
     *Rule.deduce(
-        ["z_targets", "t", "time_window", "t_num", "dt", "w_c", "w0", "w", "w_order", "l"],
-        math.build_sim_grid,
-        ["time_window", "t_num", "dt"],
-        2,
+        ["t", "time_window", "dt", "t_num"], math.build_t_grid, ["time_window", "t_num", "dt"], 2
     ),
+    Rule("z_targets", math.build_z_grid),
     Rule("adapt_step_size", lambda step_size: step_size == 0),
     Rule("dynamic_dispersion", lambda pressure: isinstance(pressure, (list, tuple, np.ndarray))),
+    Rule("w0", units.m, ["wavelength"]),
+    Rule("l", units.m.inv, ["w"]),
+    Rule("w0_ind", math.argclosest, ["w_for_disp", "w0"]),
+    Rule("w_num", len, ["w"]),
+    Rule("dw", lambda w: w[1] - w[0]),
+    Rule(["fft", "ifft"], utils.fft_functions, priorities=1),
     # Pulse
-    Rule("spec_0", np.fft.fft, ["field_0"]),
-    Rule("field_0", np.fft.ifft, ["spec_0"]),
+    Rule("field_0", pulse.finalize_pulse),
     Rule("spec_0", utils.load_previous_spectrum, ["recovery_data_dir"], priorities=4),
     Rule("spec_0", utils.load_previous_spectrum, priorities=3),
     *Rule.deduce(
@@ -301,21 +313,6 @@ default_rules: list[Rule] = [
         1,
         priorities=[2, 1, 1, 1],
     ),
-    Rule("pre_field_0", pulse.initial_field, priorities=1),
-    Rule(
-        "field_0",
-        pulse.finalize_pulse,
-        [
-            "pre_field_0",
-            "quantum_noise",
-            "w_c",
-            "w0",
-            "time_window",
-            "dt",
-            "additional_noise_factor",
-            "input_transmission",
-        ],
-    ),
     Rule("peak_power", pulse.E0_to_P0, ["energy", "t0", "shape"]),
     Rule("peak_power", pulse.soliton_num_to_peak_power),
     Rule("mean_power", pulse.energy_to_mean_power),
@@ -329,17 +326,7 @@ default_rules: list[Rule] = [
     Rule("L_NL", pulse.L_NL),
     Rule("L_sol", pulse.L_sol),
     # Fiber Dispersion
-    Rule(["wl_for_disp", "dispersion_ind"], fiber.lambda_for_dispersion),
     Rule("w_for_disp", units.m, ["wl_for_disp"]),
-    Rule("beta2_coefficients", fiber.dispersion_coefficients),
-    Rule("beta2_arr", fiber.beta2),
-    Rule("beta2_arr", fiber.dispersion_from_coefficients),
-    Rule("beta2", lambda beta2_coefficients: beta2_coefficients[0]),
-    Rule(
-        ["wl_for_disp", "beta2_arr", "interpolation_range"],
-        fiber.load_custom_dispersion,
-        priorities=[2, 2, 2],
-    ),
     Rule("hr_w", fiber.delayed_raman_w),
     Rule("n_gas_2", materials.n_gas_2),
     Rule("n_eff", fiber.n_eff_hasan, conditions=dict(model="hasan")),
@@ -351,9 +338,13 @@ default_rules: list[Rule] = [
         ["wl_for_disp", "pitch", "pitch_ratio"],
         conditions=dict(model="pcf"),
     ),
+    Rule("n0", lambda w0_ind, n_eff: n_eff[w0_ind]),
     Rule("capillary_spacing", fiber.capillary_spacing_hasan),
     Rule("capillary_resonance_strengths", fiber.capillary_resonance_strengths),
     Rule("capillary_resonance_strengths", lambda: [], priorities=-1),
+    Rule("beta_arr", fiber.beta),
+    Rule("beta1_arr", fiber.beta1),
+    Rule("beta2_arr", fiber.beta2),
     # Fiber nonlinearity
     Rule("A_eff", fiber.A_eff_from_V),
     Rule("A_eff", fiber.A_eff_from_diam),
@@ -376,32 +367,78 @@ default_rules: list[Rule] = [
         fiber.V_eff_step_index,
         ["l", "core_radius", "numerical_aperture", "interpolation_range"],
     ),
+    Rule("n2", materials.gas_n2),
+    Rule("n2", lambda: 2.2e-20, priorities=-1),
+    # operators
+    Rule("n_op", operators.ConstantRefractiveIndex),
+    Rule("n_op", operators.MarcatiliRefractiveIndex),
+    Rule("n_op", operators.MarcatiliAdjustedRefractiveIndex),
+    Rule("n_op", operators.HasanRefractiveIndex),
+    Rule("raman_op", operators.NoRaman, priorities=-1),
+    Rule("loss_op", operators.NoLoss, priorities=-1),
+    Rule("plasma_op", operators.NoPlasma, priorities=-1),
+    Rule("conserved_quantity", operators.NoConservedQuantity, priorities=-1),
+]
+
+envelope_rules = default_rules + [
+    # Grid
+    Rule(["w_c", "w", "w_order"], math.build_envelope_w_grid),
+    # Pulse
+    Rule("pre_field_0", pulse.initial_field_envelope, priorities=1),
+    Rule("spec_0", np.fft.fft, ["field_0"]),
+    Rule("field_0", np.fft.ifft, ["spec_0"]),
+    # Dispersion
+    Rule(["wl_for_disp", "dispersion_ind"], fiber.lambda_for_envelope_dispersion),
+    Rule("beta2_coefficients", fiber.dispersion_coefficients),
+    Rule("beta2_arr", fiber.dispersion_from_coefficients),
+    Rule("beta2", lambda beta2_coefficients: beta2_coefficients[0]),
+    Rule(
+        ["wl_for_disp", "beta2_arr", "interpolation_range"],
+        fiber.load_custom_dispersion,
+        priorities=[2, 2, 2],
+    ),
+    # Nonlinearity
     Rule("gamma", lambda gamma_arr: gamma_arr[0], priorities=-1),
     Rule("gamma", fiber.gamma_parameter),
     Rule("gamma_arr", fiber.gamma_parameter, ["n2", "w0", "A_eff_arr"]),
-    Rule("n2", materials.gas_n2),
-    Rule("n2", lambda: 2.2e-20, priorities=-1),
     # Operators
     Rule("gamma_op", operators.ConstantGamma, priorities=1),
     Rule("gamma_op", operators.ConstantScalarGamma),
     Rule("gamma_op", operators.NoGamma, priorities=-1),
     Rule("ss_op", operators.SelfSteepening),
     Rule("ss_op", operators.NoSelfSteepening, priorities=-1),
+    Rule("spm_op", operators.NoEnvelopeSPM, priorities=-1),
     Rule("spm_op", operators.EnvelopeSPM),
-    Rule("spm_op", operators.NoSPM, priorities=-1),
     Rule("raman_op", operators.EnvelopeRaman),
-    Rule("raman_op", operators.NoRaman, priorities=-1),
     Rule("nonlinear_operator", operators.EnvelopeNonLinearOperator),
     Rule("loss_op", operators.CustomLoss, priorities=3),
     Rule("loss_op", operators.CapillaryLoss, priorities=2, conditions=dict(loss="capillary")),
     Rule("loss_op", operators.ConstantLoss, priorities=1),
-    Rule("loss_op", operators.NoLoss, priorities=-1),
-    Rule("n_op", operators.ConstantRefractiveIndex),
-    Rule("n_op", operators.MarcatiliRefractiveIndex),
-    Rule("n_op", operators.MarcatiliAdjustedRefractiveIndex),
-    Rule("n_op", operators.HasanRefractiveIndex),
     Rule("dispersion_op", operators.ConstantPolyDispersion),
     Rule("dispersion_op", operators.DirectDispersion),
     Rule("linear_operator", operators.EnvelopeLinearOperator),
     Rule("conserved_quantity", operators.conserved_quantity),
 ]
+
+full_field_rules = default_rules + [
+    # Grid
+    Rule(["w", "w_order", "l"], math.build_full_field_w_grid, priorities=1),
+    # Pulse
+    Rule("spec_0", np.fft.rfft, ["field_0"]),
+    Rule("field_0", np.fft.irfft, ["spec_0"]),
+    Rule("pre_field_0", pulse.initial_full_field),
+    # Dispersion
+    Rule(["wl_for_disp", "dispersion_ind"], fiber.lambda_for_full_field_dispersion),
+    Rule("frame_velocity", fiber.frame_velocity),
+    # Nonlinearity
+    Rule("chi3", materials.gas_chi3),
+    # Operators
+    Rule("spm_op", operators.FullFieldSPM),
+    Rule("spm_op", operators.NoFullFieldSPM, priorities=-1),
+    Rule("beta_op", operators.ConstantWaveVector),
+    Rule(
+        "linear_operator",
+        operators.FullFieldLinearOperator,
+    ),
+    Rule("nonlinear_operator", operators.FullFieldNonLinearOperator),
+]
diff --git a/src/scgenerator/math.py b/src/scgenerator/math.py
index 1fe28b5..b50f519 100644
--- a/src/scgenerator/math.py
+++ b/src/scgenerator/math.py
@@ -252,68 +252,82 @@ def tspace(time_window=None, t_num=None, dt=None):
         raise TypeError("not enough parameter to determine time vector")
 
 
-def build_sim_grid(
-    length: float,
-    z_num: int,
-    wavelength: float,
-    time_window: float = None,
-    t_num: int = None,
-    dt: float = None,
-) -> tuple[np.ndarray, np.ndarray, float, int, float, np.ndarray, float, np.ndarray, np.ndarray]:
+def build_envelope_w_grid(t: np.ndarray, w0: float) -> tuple[np.ndarray, np.ndarray, np.ndarray]:
     """computes a bunch of values that relate to the simulation grid
 
     Parameters
     ----------
-    length : float
-        length of the fiber in m
-    z_num : int
-        number of spatial points
-    wavelength : float
-        pump wavelength in m
-    deg : int
-        dispersion interpolation degree
-    time_window : float, optional
-        total width of the temporal grid in s, by default None
-    t_num : int, optional
-        number of temporal grid points, by default None
-    dt : float, optional
-        spacing of the temporal grid in s, by default None
+    t : np.ndarray, shape (t_num,)
+        time array
+    w0 : float
+        center frequency
+
+    Returns
+    -------
+    w_c : np.ndarray, shape (n, )
+        centered angular frequencies in rad/s where 0 is the pump frequency
+    w : np.ndarray, shape (n, )
+        angular frequency grid
+    w_order : np.ndarray, shape (n,)
+        arrays of indices such that w[w_order] is sorted
+    """
+    w_c = wspace(t)
+    w = w_c + w0
+    w_order = np.argsort(w)
+    return w_c, w, w_order
+
+
+def build_full_field_w_grid(t_num: int, dt: float) -> tuple[np.ndarray, float, float, int]:
+    """
+    Paramters
+    ---------
+    t_num : int
+        number of temporal sampling points
+    dt : float
+        uniform spacing between sample points
+
+    Returns
+    -------
+    w : np.ndarray, shape (n, )
+        angular frequency grid
+    w_order : np.ndarray, shape (n,)
+        arrays of indices such that w[w_order] is sorted
+    """
+    w = 2 * pi * np.fft.rfftfreq(t_num, dt)
+    w_order = np.argsort(w)
+    ind = w != 0
+    l = np.zeros(len(w))
+    l[ind] = 2 * pi * c / w[ind]
+    if any(ind):
+        l[~ind] = 2 * pi * c / (np.abs(w[ind]).min())
+    return w, w_order, l
+
+
+def build_z_grid(z_num: int, length: float) -> np.ndarray:
+    return np.linspace(0, length, z_num)
+
+
+def build_t_grid(
+    time_window: float = None, t_num: int = None, dt: float = None
+) -> tuple[np.ndarray, float, float, int]:
+    """[summary]
 
     Returns
     -------
-    z_targets : np.ndarray, shape (z_num, )
-        spatial points in m
     t : np.ndarray, shape (t_num, )
         temporal points in s
     time_window : float
         total width of the temporal grid in s, by default None
-    t_num : int
-        number of temporal grid points, by default None
     dt : float
         spacing of the temporal grid in s, by default None
-    w_c : np.ndarray, shape (t_num, )
-        centered angular frequencies in rad/s where 0 is the pump frequency
-    w0 : float
-        pump angular frequency
-    w : np.ndarray, shape (t_num, )
-        actual angualr frequency grid in rad/s
-    w_order : np.ndarray, shape (t_num, )
-        result of w.argsort()
-    l : np.ndarray, shape (t_num)
-        wavelengths in m
+    t_num : int
+        number of temporal grid points, by default None
     """
     t = tspace(time_window, t_num, dt)
-
     time_window = t.max() - t.min()
     dt = t[1] - t[0]
     t_num = len(t)
-    z_targets = np.linspace(0, length, z_num)
-    w_c = wspace(t)
-    w0 = 2 * pi * c / wavelength
-    w = w_c + w0
-    w_order = np.argsort(w)
-    l = 2 * pi * c / w
-    return z_targets, t, time_window, t_num, dt, w_c, w0, w, w_order, l
+    return t, time_window, dt, t_num
 
 
 def polynom_extrapolation(x: np.ndarray, y: np.ndarray, degree: float) -> np.ndarray:
diff --git a/src/scgenerator/operators.py b/src/scgenerator/operators.py
index d4fabc1..e59a3e5 100644
--- a/src/scgenerator/operators.py
+++ b/src/scgenerator/operators.py
@@ -7,7 +7,7 @@ from __future__ import annotations
 import dataclasses
 from abc import ABC, abstractmethod
 from dataclasses import dataclass
-from typing import Any
+from typing import Any, Callable
 
 import numpy as np
 from scipy.interpolate import interp1d
@@ -23,11 +23,13 @@ class SpectrumDescriptor:
     name: str
     value: np.ndarray = None
     _counter = 0
+    _full_field: bool = False
+    _converter: Callable[[np.ndarray], np.ndarray]
 
     def __set__(self, instance: CurrentState, value: np.ndarray):
         self._counter += 1
         instance.spec2 = math.abs2(value)
-        instance.field = np.fft.ifft(value)
+        instance.field = instance.converter(value)
         instance.field2 = math.abs2(instance.field)
         self.value = value
 
@@ -38,6 +40,9 @@ class SpectrumDescriptor:
         raise AttributeError("Cannot delete Spectrum field")
 
     def __set_name__(self, owner, name):
+        for field_name in ["converter", "field", "field2", "spec2"]:
+            if not hasattr(owner, field_name):
+                raise AttributeError(f"{owner!r} doesn't have a {field_name!r} attribute")
         self.name = name
 
 
@@ -47,6 +52,7 @@ class CurrentState:
     z: float
     h: float
     C_to_A_factor: np.ndarray
+    converter: Callable[[np.ndarray], np.ndarray] = np.fft.ifft
     spectrum: np.ndarray = SpectrumDescriptor()
     spec2: np.ndarray = dataclasses.field(init=False)
     field: np.ndarray = dataclasses.field(init=False)
@@ -57,7 +63,9 @@ class CurrentState:
         return self.z / self.length
 
     def replace(self, new_spectrum) -> CurrentState:
-        return CurrentState(self.length, self.z, self.h, self.C_to_A_factor, new_spectrum)
+        return CurrentState(
+            self.length, self.z, self.h, self.C_to_A_factor, self.converter, new_spectrum
+        )
 
 
 class Operator(ABC):
@@ -82,10 +90,21 @@ class Operator(ABC):
         pass
 
 
-class NoOp:
+class NoOpTime(Operator):
     def __init__(self, t_num: int):
         self.arr_const = np.zeros(t_num)
 
+    def __call__(self, state: CurrentState) -> np.ndarray:
+        return self.arr_const
+
+
+class NoOpFreq(Operator):
+    def __init__(self, w_num: int):
+        self.arr_const = np.zeros(w_num)
+
+    def __call__(self, state: CurrentState) -> np.ndarray:
+        return self.arr_const
+
 
 ##################################################
 ###################### GAS #######################
@@ -440,12 +459,17 @@ class ConstantWaveVector(AbstractWaveVector):
         self,
         n_op: ConstantRefractiveIndex,
         w_for_disp: np.ndarray,
-        t_num: int,
+        w_num: int,
         dispersion_ind: np.ndarray,
+        w_order: np.ndarray,
     ):
 
-        self.beta_arr = np.zeros(t_num, dtype=float)
+        self.beta_arr = np.zeros(w_num, dtype=float)
         self.beta_arr[dispersion_ind] = fiber.beta(w_for_disp, n_op())[2:-2]
+        left_ind, *_, right_ind = np.nonzero(self.beta_arr[w_order])[0]
+        self.beta_arr[w_order] = math._polynom_extrapolation_in_place(
+            self.beta_arr[w_order], left_ind, right_ind, 1.0
+        )
 
     def __call__(self, state: CurrentState) -> np.ndarray:
         return self.beta_arr
@@ -475,16 +499,16 @@ class AbstractLoss(Operator):
 class ConstantLoss(AbstractLoss):
     arr_const: np.ndarray
 
-    def __init__(self, alpha: float, t_num: int):
-        self.arr_const = alpha * np.ones(t_num)
+    def __init__(self, alpha: float, w_num: int):
+        self.arr_const = alpha * np.ones(w_num)
 
     def __call__(self, state: CurrentState = None) -> np.ndarray:
         return self.arr_const
 
 
 class NoLoss(ConstantLoss):
-    def __init__(self, t_num: int):
-        super().__init__(0, t_num)
+    def __init__(self, w_num: int):
+        super().__init__(0, w_num)
 
 
 class CapillaryLoss(ConstantLoss):
@@ -492,12 +516,12 @@ class CapillaryLoss(ConstantLoss):
         self,
         wl_for_disp: np.ndarray,
         dispersion_ind: np.ndarray,
-        t_num: int,
+        w_num: int,
         core_radius: float,
         he_mode: tuple[int, int],
     ):
         alpha = fiber.capillary_loss(wl_for_disp, he_mode, core_radius)
-        self.arr = np.zeros(t_num)
+        self.arr = np.zeros(w_num)
         self.arr[dispersion_ind] = alpha[2:-2]
 
     def __call__(self, state: CurrentState = None) -> np.ndarray:
@@ -538,9 +562,8 @@ class AbstractRaman(Operator):
         """
 
 
-class NoRaman(NoOp, AbstractRaman):
-    def __call__(self, state: CurrentState) -> np.ndarray:
-        return self.arr_const
+class NoRaman(NoOpTime, AbstractRaman):
+    pass
 
 
 class EnvelopeRaman(AbstractRaman):
@@ -585,9 +608,12 @@ class AbstractSPM(Operator):
         """
 
 
-class NoSPM(NoOp, AbstractSPM):
-    def __call__(self, state: CurrentState) -> np.ndarray:
-        return self.arr_const
+class NoEnvelopeSPM(NoOpFreq, AbstractSPM):
+    pass
+
+
+class NoFullFieldSPM(NoOpTime, AbstractSPM):
+    pass
 
 
 class EnvelopeSPM(AbstractSPM):
@@ -599,11 +625,12 @@ class EnvelopeSPM(AbstractSPM):
 
 
 class FullFieldSPM(AbstractSPM):
-    def __init__(self, raman_op: AbstractRaman):
+    def __init__(self, raman_op: AbstractRaman, chi3: float):
         self.fraction = 1 - raman_op.f_r
+        self.factor = self.fraction * chi3 * units.epsilon0
 
     def __call__(self, state: CurrentState) -> np.ndarray:
-        return self.fraction * state.field2
+        return self.fraction * state.field2 * state.field
 
 
 ##################################################
@@ -627,9 +654,8 @@ class AbstractSelfSteepening(Operator):
         """
 
 
-class NoSelfSteepening(NoOp, AbstractSelfSteepening):
-    def __call__(self, state: CurrentState) -> np.ndarray:
-        return self.arr_const
+class NoSelfSteepening(NoOpFreq, AbstractSelfSteepening):
+    pass
 
 
 class SelfSteepening(AbstractSelfSteepening):
@@ -692,9 +718,8 @@ class Plasma(Operator):
     pass
 
 
-class NoPlasma(NoOp, Plasma):
-    def __call__(self, state: CurrentState) -> np.ndarray:
-        return self.arr_const
+class NoPlasma(NoOpTime, Plasma):
+    pass
 
 
 ##################################################
@@ -786,50 +811,43 @@ def conserved_quantity(
 ##################################################
 
 
-class EnvelopeLinearOperator(Operator):
+class LinearOperator(Operator):
+    def __call__(self, state: CurrentState) -> np.ndarray:
+        """returns the linear operator to be multiplied by the spectrum in the frequency domain
+
+        Parameters
+        ----------
+        state : CurrentState
+
+        Returns
+        -------
+        np.ndarray
+            linear component
+        """
+
+
+class EnvelopeLinearOperator(LinearOperator):
     def __init__(self, dispersion_op: AbstractDispersion, loss_op: AbstractLoss):
         self.dispersion_op = dispersion_op
         self.loss_op = loss_op
 
     def __call__(self, state: CurrentState) -> np.ndarray:
-        """returns the linear operator to be multiplied by the spectrum in the frequency domain
-
-        Parameters
-        ----------
-        state : CurrentState
-
-        Returns
-        -------
-        np.ndarray
-            linear component
-        """
         return self.dispersion_op(state) - self.loss_op(state) / 2
 
 
-class FullFieldLinearOperator(Operator):
+class FullFieldLinearOperator(LinearOperator):
     def __init__(
         self,
-        wave_vector: AbstractWaveVector,
+        beta_op: AbstractWaveVector,
         loss_op: AbstractLoss,
-        reference_velocity: float,
+        frame_velocity: float,
         w: np.ndarray,
     ):
-        self.delay = w / reference_velocity
-        self.wave_vector = wave_vector
+        self.delay = w / frame_velocity
+        self.wave_vector = beta_op
         self.loss_op = loss_op
 
     def __call__(self, state: CurrentState) -> np.ndarray:
-        """returns the linear operator to be multiplied by the spectrum in the frequency domain
-
-        Parameters
-        ----------
-        state : CurrentState
-
-        Returns
-        -------
-        np.ndarray
-            linear component
-        """
         return 1j * (self.wave_vector(state) - self.delay) - self.loss_op(state) / 2
 
 
@@ -877,10 +895,20 @@ class EnvelopeNonLinearOperator(NonLinearOperator):
 
 
 class FullFieldNonLinearOperator(NonLinearOperator):
-    def __init__(self, raman_op: AbstractRaman, spm_op: AbstractSPM, plasma_op: Plasma):
+    def __init__(
+        self,
+        raman_op: AbstractRaman,
+        spm_op: AbstractSPM,
+        plasma_op: Plasma,
+        w: np.ndarray,
+        beta_op: AbstractWaveVector,
+    ):
         self.raman_op = raman_op
         self.spm_op = spm_op
         self.plasma_op = plasma_op
+        self.factor = 1j * w ** 2 / (2.0 * units.c ** 2 * units.epsilon0)
+        self.beta_op = beta_op
 
     def __call__(self, state: CurrentState) -> np.ndarray:
-        return self.spm_op(state) + self.raman_op(state) + self.plasma_op(state)
+        total_nonlinear = self.spm_op(state) + self.raman_op(state) + self.plasma_op(state)
+        return self.factor / self.beta_op(state) * np.fft.rfft(total_nonlinear)
diff --git a/src/scgenerator/parameter.py b/src/scgenerator/parameter.py
index 20049fc..5db0785 100644
--- a/src/scgenerator/parameter.py
+++ b/src/scgenerator/parameter.py
@@ -18,7 +18,12 @@ from .const import MANDATORY_PARAMETERS, PARAM_FN, VALID_VARIABLE, __version__
 from .errors import EvaluatorError
 from .evaluator import Evaluator
 from .logger import get_logger
-from .operators import AbstractConservedQuantity, EnvelopeLinearOperator, NonLinearOperator
+from .operators import (
+    AbstractConservedQuantity,
+    EnvelopeLinearOperator,
+    LinearOperator,
+    NonLinearOperator,
+)
 from .utils import fiber_folder, update_path_name
 from .variationer import VariationDescriptor, Variationer
 
@@ -81,6 +86,11 @@ def boolean(name, n):
         raise ValueError(f"{name!r} must be True or False")
 
 
+def is_function(name, n):
+    if not callable(n):
+        raise TypeError(f"{name!r} must be callable")
+
+
 @lru_cache
 def non_negative(*types):
     @type_checker(*types)
@@ -294,6 +304,7 @@ class Parameters:
     input_transmission: float = Parameter(in_range_incl(0, 1), default=1.0)
     gamma: float = Parameter(non_negative(float, int))
     n2: float = Parameter(non_negative(float, int))
+    chi3: float = Parameter(non_negative(float, int))
     loss: str = Parameter(literal("capillary"))
     loss_file: str = Parameter(string)
     effective_mode_diameter: float = Parameter(positive(float, int))
@@ -348,6 +359,7 @@ class Parameters:
     t0: float = Parameter(in_range_excl(0, 1e-9), display_info=(1e15, "fs"))
 
     # simulation
+    full_field: bool = Parameter(boolean, default=False)
     raman_type: str = Parameter(literal("measured", "agrawal", "stolen"), converter=str.lower)
     self_steepening: bool = Parameter(boolean, default=True)
     spm: bool = Parameter(boolean, default=True)
@@ -367,11 +379,13 @@ class Parameters:
     worker_num: int = Parameter(positive(int))
 
     # computed
-    linear_operator: EnvelopeLinearOperator = Parameter(type_checker(EnvelopeLinearOperator))
+    linear_operator: LinearOperator = Parameter(type_checker(LinearOperator))
     nonlinear_operator: NonLinearOperator = Parameter(type_checker(NonLinearOperator))
     conserved_quantity: AbstractConservedQuantity = Parameter(
         type_checker(AbstractConservedQuantity)
     )
+    fft: Callable[[np.ndarray], np.ndarray] = Parameter(is_function)
+    ifft: Callable[[np.ndarray], np.ndarray] = Parameter(is_function)
     field_0: np.ndarray = Parameter(type_checker(np.ndarray))
     spec_0: np.ndarray = Parameter(type_checker(np.ndarray))
     beta2: float = Parameter(type_checker(int, float))
@@ -397,7 +411,7 @@ class Parameters:
     version: str = Parameter(string)
 
     def __post_init__(self):
-        self._evaluator = Evaluator.default()
+        self._evaluator = Evaluator.default(self.full_field)
         self._evaluator.set(self._param_dico)
 
     def __repr__(self) -> str:
@@ -423,6 +437,9 @@ class Parameters:
         for k in to_compute:
             getattr(self, k)
 
+    def compute(self, key: str) -> Any:
+        return self._evaluator.compute(key)
+
     def pformat(self) -> str:
         return "\n".join(
             f"{k} = {VariationDescriptor.format_value(k, v)}" for k, v in self.dump_dict().items()
diff --git a/src/scgenerator/physics/fiber.py b/src/scgenerator/physics/fiber.py
index 1789dec..f097887 100644
--- a/src/scgenerator/physics/fiber.py
+++ b/src/scgenerator/physics/fiber.py
@@ -17,10 +17,10 @@ pipi = 2 * pi
 T = TypeVar("T")
 
 
-def lambda_for_dispersion(
+def lambda_for_envelope_dispersion(
     l: np.ndarray, interpolation_range: tuple[float, float]
 ) -> tuple[np.ndarray, np.ndarray]:
-    """Returns a wl vector for dispersion calculation
+    """Returns a wl vector for dispersion calculation in envelope mode
 
     Returns
     -------
@@ -31,6 +31,12 @@ def lambda_for_dispersion(
         indices of the original l where the values are valid (i.e. without the two extra on each side)
     """
     su = np.where((l >= interpolation_range[0]) & (l <= interpolation_range[1]))[0]
+    if l[su].min() > 1.01 * interpolation_range[0]:
+        raise ValueError(
+            f"lower range of {1e9*interpolation_range[0]:.1f}nm is not reached by the grid. "
+            "try a finer grid"
+        )
+
     ind_above_cond = su >= len(l) // 2
     ind_above = su[ind_above_cond]
     ind_below = su[~ind_above_cond]
@@ -41,6 +47,29 @@ def lambda_for_dispersion(
     return l_out, ind_out
 
 
+def lambda_for_full_field_dispersion(
+    l: np.ndarray, interpolation_range: tuple[float, float]
+) -> tuple[np.ndarray, np.ndarray]:
+    """Returns a wl vector for dispersion calculation in full field mode
+
+    Returns
+    -------
+    np.ndarray
+        subset of l in the interpolation range with two extra values on each side
+        to accomodate for taking gradients
+    np.ndarray
+        indices of the original l where the values are valid (i.e. without the two extra on each side)
+    """
+    su = np.where((l >= interpolation_range[0]) & (l <= interpolation_range[1]))[0]
+    if l[su].min() > 1.01 * interpolation_range[0]:
+        raise ValueError(
+            f"lower range of {1e9*interpolation_range[0]:.1f}nm is not reached by the grid. "
+            "try a finer grid"
+        )
+    fu = np.concatenate((su[:2] - 2, su, su[-2:] + 2))
+    return l[fu], su
+
+
 def is_dynamic_dispersion(pressure=None):
     """tests if the parameter dictionary implies that the dispersion profile of the fiber changes with z
 
@@ -598,6 +627,10 @@ def beta2(w_for_disp: np.ndarray, n_eff: np.ndarray) -> np.ndarray:
     return np.gradient(np.gradient(beta(w_for_disp, n_eff), w_for_disp), w_for_disp)
 
 
+def frame_velocity(beta1_arr: np.ndarray, w0_ind: int) -> float:
+    return 1.0 / beta1_arr[w0_ind]
+
+
 def HCPCF_dispersion(
     wl_for_disp,
     material_dico=None,
diff --git a/src/scgenerator/physics/materials.py b/src/scgenerator/physics/materials.py
index 1a9142c..cda8c74 100644
--- a/src/scgenerator/physics/materials.py
+++ b/src/scgenerator/physics/materials.py
@@ -1,14 +1,12 @@
-from typing import Any, Callable
+from typing import Any
 
 import numpy as np
-import scipy.special
-from scipy.integrate import cumulative_trapezoid
 
 from .. import utils
 from ..cache import np_cache
 from ..logger import get_logger
 from . import units
-from .units import NA, c, e, hbar, kB, me, epsilon0
+from .units import NA, c, kB, epsilon0
 
 
 @np_cache
@@ -112,24 +110,46 @@ def number_density_van_der_waals(
     return np.min(roots)
 
 
-def sellmeier(lambda_, material_dico, pressure=None, temperature=None):
-    """reads a file containing the Sellmeier values corresponding to the choses material and returns the real susceptibility
-    pressure and temperature adjustments are made according to ideal gas law.
+def sellmeier_scalar(
+    wavelength: float,
+    material_dico: dict[str, Any],
+    pressure: float = None,
+    temperature: float = None,
+) -> float:
+    return float(sellmeier(np.array([wavelength]), material_dico, pressure, temperature)[0])
+
+
+def sellmeier(
+    wl_for_disp: np.ndarray,
+    material_dico: dict[str, Any],
+    pressure: float = None,
+    temperature: float = None,
+) -> np.ndarray:
+    """reads a file containing the Sellmeier values corresponding to the choses material and
+    returns the real susceptibility pressure and temperature adjustments are made according to
+    ideal gas law.
+
     Parameters
     ----------
-        lambda_ : wl vector over which to compute the refractive index
-        material_dico : material dictionary as explained in scgenerator.utils.load_material_dico
-        pressure : pressure in mbar if material is a gas. Can be a constant or a tupple if a presure gradient is considered
-        temperature : temperature of the gas in Kelvin
+    wl_for_disp : array, shape (n,)
+        wavelength vector over which to compute the refractive index
+    material_dico : dict[str, Any]
+        material dictionary as explained in scgenerator.utils.load_material_dico
+    pressure : float, optional
+        pressure in Pa, by default None
+    temperature : float, optional
+        temperature of the gas in Kelvin
+
     Returns
-    ----------
-        an array n(lambda_)^2 - 1
+    -------
+    array, shape (n,)
+        chi = n^2 - 1
     """
     logger = get_logger(__name__)
 
     WL_THRESHOLD = 8.285e-6
-    ind = lambda_ < WL_THRESHOLD
-    temp_l = lambda_[ind]
+    ind = wl_for_disp < WL_THRESHOLD
+    temp_l = wl_for_disp[ind]
 
     B = material_dico["sellmeier"]["B"]
     C = material_dico["sellmeier"]["C"]
@@ -138,7 +158,7 @@ def sellmeier(lambda_, material_dico, pressure=None, temperature=None):
     t0 = material_dico["sellmeier"].get("t0", 273.15)
     kind = material_dico["sellmeier"].get("kind", 1)
 
-    chi = np.zeros_like(lambda_)  # = n^2 - 1
+    chi = np.zeros_like(wl_for_disp)  # = n^2 - 1
     if kind == 1:
         logger.debug("materials : using Sellmeier 1st kind equation")
         for b, c_ in zip(B, C):
@@ -251,17 +271,15 @@ def gas_chi3(gas_name: str, wavelength: float, pressure: float, temperature: flo
         [description]
     """
     mat_dico = utils.load_material_dico(gas_name)
-    chi = sellmeier(wavelength, mat_dico, pressure=pressure, temperature=temperature)
+    chi = sellmeier_scalar(wavelength, mat_dico, pressure=pressure, temperature=temperature)
     return n2_to_chi3(
         non_linear_refractive_index(mat_dico, pressure, temperature), np.sqrt(chi + 1)
     )
 
 
 def n2_to_chi3(n2: float, n0: float) -> float:
-    return n2 / 3.0 * 4 * epsilon0 * n0 * c ** 2
+    return n2 * 4 * epsilon0 * n0 ** 2 * c / 3
 
 
 def chi3_to_n2(chi3: float, n0: float) -> float:
     return 3.0 * chi3 / (4.0 * epsilon0 * c * n0 ** 2)
-
-
diff --git a/src/scgenerator/physics/pulse.py b/src/scgenerator/physics/pulse.py
index 86b0a8c..c3f0099 100644
--- a/src/scgenerator/physics/pulse.py
+++ b/src/scgenerator/physics/pulse.py
@@ -94,7 +94,37 @@ class PulseProperties:
         return [cls(*a) for a in arr]
 
 
-def initial_field(t: np.ndarray, shape: str, t0: float, peak_power: float) -> np.ndarray:
+def initial_full_field(
+    t: np.ndarray, shape: str, A_eff: float, t0: float, peak_power: float, w0: float, n0: float
+) -> np.ndarray:
+    """initial field in full field simulations
+
+    Parameters
+    ----------
+    t : np.ndarray, shape(n, )
+        time array
+    shape : str
+        gaussian or sech
+    t0 : float
+        t0 parameter
+    peak_power : float
+        peak power in W
+    w0 : float
+        center frequency
+    n0 : float
+        refractive index at center frequency
+
+    Returns
+    -------
+    np.ndarray, shape (n,)
+        initial field
+    """
+    return (
+        initial_field_envelope(t, shape, t0, peak_power) * np.cos(w0 * t) * units.W_to_Vm(n0, A_eff)
+    )
+
+
+def initial_field_envelope(t: np.ndarray, shape: str, t0: float, peak_power: float) -> np.ndarray:
     """returns the initial field
 
     Parameters
@@ -417,15 +447,13 @@ def technical_noise(rms_noise, noise_correlation=-0.4):
     return psy, 1 + noise_correlation * (psy - 1)
 
 
-def shot_noise(w_c, w0, T, dt, additional_noise_factor=1.0):
+def shot_noise(w: np.ndarray, T: float, dt: float, additional_noise_factor=1.0):
     """
 
     Parameters
     ----------
-        w_c : 1D array
+        w_c : array, shape (n,)
             angular frequencies centered around 0
-        w0 : float
-            pump angular frequency
         T : float
             length of the time windows
         dt : float
@@ -435,28 +463,27 @@ def shot_noise(w_c, w0, T, dt, additional_noise_factor=1.0):
 
     Returns
     -------
-        out : 1D array of size len(w_c)
+        out : array, shape (n,)
             noise field to be added on top of initial field in time domain
     """
-    rand_phase = np.random.rand(len(w_c)) * 2 * pi
-    A_oppm = np.sqrt(hbar * (np.abs(w_c + w0)) * T) * np.exp(-1j * rand_phase)
+    rand_phase = np.random.rand(len(w)) * 2 * pi
+    A_oppm = np.sqrt(hbar * (np.abs(w)) * T) * np.exp(-1j * rand_phase)
     out = ifft(A_oppm / dt * np.sqrt(2 * pi))
     return out * additional_noise_factor
 
 
 def finalize_pulse(
-    field_0: np.ndarray,
+    pre_field_0: np.ndarray,
     quantum_noise: bool,
-    w_c: bool,
-    w0: float,
+    w: np.ndarray,
     time_window: float,
     dt: float,
     additional_noise_factor: float,
     input_transmission: float,
 ) -> np.ndarray:
     if quantum_noise:
-        field_0 = field_0 + shot_noise(w_c, w0, time_window, dt, additional_noise_factor)
-    return np.sqrt(input_transmission) * field_0
+        pre_field_0 = pre_field_0 + shot_noise(w, time_window, dt, additional_noise_factor)
+    return np.sqrt(input_transmission) * pre_field_0
 
 
 def mean_phase(spectra):
diff --git a/src/scgenerator/physics/simulate.py b/src/scgenerator/physics/simulate.py
index e8016eb..b5b5809 100644
--- a/src/scgenerator/physics/simulate.py
+++ b/src/scgenerator/physics/simulate.py
@@ -107,6 +107,7 @@ class RK4IP:
             z=z,
             h=initial_h,
             C_to_A_factor=C_to_A_factor,
+            converter=self.params.ifft,
             spectrum=self.params.spec_0.copy() / C_to_A_factor,
         )
         self.stored_spectra = self.params.recovery_last_stored * [None] + [
diff --git a/src/scgenerator/physics/units.py b/src/scgenerator/physics/units.py
index 64b147d..998bfd8 100644
--- a/src/scgenerator/physics/units.py
+++ b/src/scgenerator/physics/units.py
@@ -16,6 +16,7 @@ epsilon0 = 8.85418781e-12
 me = 9.1093837015e-31
 e = 1.602176634e-19
 
+
 prefix = dict(P=1e12, G=1e9, M=1e6, k=1e3, d=1e-1, c=1e-2, m=1e-3, u=1e-6, n=1e-9, p=1e-12, f=1e-15)
 
 """
@@ -37,6 +38,22 @@ class To:
 units_map = dict()
 
 
+def W_to_Vm(n0: float, A_eff: float) -> float:
+    """returns the factor to convert from [|E|²] = W to [|E|] = V/m
+
+    Parameters
+    ----------
+    n : float
+        refractive index
+
+    Returns
+    -------
+    float
+        p such that E_sqrt(W) * p = W_Vm
+    """
+    return 1.0 / np.sqrt(A_eff * 0.5 * epsilon0 * c * n0)
+
+
 def unit(tpe: str, label: str, inv: Callable = None):
     def unit_maker(func):
         nonlocal inv
diff --git a/src/scgenerator/utils.py b/src/scgenerator/utils.py
index 6c3ca5e..8f782fd 100644
--- a/src/scgenerator/utils.py
+++ b/src/scgenerator/utils.py
@@ -404,6 +404,15 @@ def _mock_function(num_args: int, num_returns: int) -> Callable:
     return out_func
 
 
+def fft_functions(
+    full_field: bool,
+) -> tuple[Callable[[np.ndarray], np.ndarray], Callable[[np.ndarray], np.ndarray]]:
+    if full_field:
+        return np.fft.rfft, np.fft.irfft
+    else:
+        return np.fft.fft, np.fft.ifft
+
+
 def combine_simulations(path: Path, dest: Path = None):
     """combines raw simulations into one folder per branch
 
diff --git a/testing/configs/Chang2011Fig2.toml b/testing/configs/Chang2011Fig2.toml
new file mode 100644
index 0000000..957977e
--- /dev/null
+++ b/testing/configs/Chang2011Fig2.toml
@@ -0,0 +1,19 @@
+name = "/Users/benoitsierro/tests/test_sc/Chang2011Fig2"
+
+wavelength = 800e-9
+shape = "gaussian"
+energy = 2.5e-6
+width = 30e-15
+
+core_radius = 10e-6
+model = "marcatili"
+gas_name = "argon"
+pressure = 1e5
+
+length = 0.1
+interpolation_range = [100e-9, 3000e-9]
+full_field = true
+dt = 0.1e-15
+t_num = 32768
+z_num = 128
+step_size = 2e-6
diff --git a/testing/test_full_field.py b/testing/test_full_field.py
new file mode 100644
index 0000000..9e80029
--- /dev/null
+++ b/testing/test_full_field.py
@@ -0,0 +1,37 @@
+import warnings
+
+import matplotlib.pyplot as plt
+import numpy as np
+import scgenerator as sc
+from customfunc.app import PlotApp
+from scgenerator.physics.simulate import RK4IP
+from customfunc import pprint
+
+warnings.filterwarnings("error")
+
+
+def main():
+    params = sc.Parameters.load("testing/configs/Chang2011Fig2.toml")
+    x = params.l * 1e9
+    o = np.argsort(x)
+    x = x[o]
+
+    plt.plot(x, sc.abs2(params.spec_0[o]))
+    state = sc.operators.CurrentState(
+        params.length, 0, params.step_size, 1.0, params.ifft, params.spec_0
+    )
+    # expD = np.exp(state.h / 2 * params.linear_operator(state))
+    # plt.plot(x, expD.imag[o], x, expD.real[o])
+    plt.plot(x, sc.abs2(params.nonlinear_operator(state))[o])
+    plt.yscale("log")
+    plt.xlim(100, 2000)
+    plt.show()
+
+    # for *_, spec in RK4IP(params).irun():
+    #     plt.plot(w[2:-2], sc.abs2(spec[ind]))
+    #     plt.show()
+    #     plt.close()
+
+
+if __name__ == "__main__":
+    main()