n2 is now computed with HC-PCFs

src/scgenerator/_utils/parameter.py

@@ -355,7 +355,7 @@ class Parameters(_AbstractParameters):
     # # fiber
     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), default=2.2e-20)
+    n2: float = Parameter(non_negative(float, int))
     loss: str = Parameter(literal("capillary"))
     loss_file: str = Parameter(string)
     effective_mode_diameter: float = Parameter(positive(float, int))
@@ -702,9 +702,7 @@ class Evaluator:
                 error = None
 
             # try every rule until one succeeds
-            for ii, rule in enumerate(
-                filter(lambda r: self.validate_condition(r), self.rules[target])
-            ):
+            for ii, rule in enumerate(filter(self.validate_condition, self.rules[target])):
                 self.logger.debug(
                     prefix + f"attempt {ii+1} to compute {target}, this time using {rule!r}"
                 )
@@ -747,9 +745,13 @@ class Evaluator:
             else:
                 default = self.get_default(target)
                 if default is None:
-                    error = NoDefaultError(prefix + f"No default provided for {target}. Current lookup cycle : {self.__curent_lookup!r}")
+                    error = NoDefaultError(
+                        prefix
+                        + f"No default provided for {target}. Current lookup cycle : {self.__curent_lookup!r}"
+                    )
                 else:
                     value = default
+                    self.logger.info(f"using default value of {value} for {target}")
                     self.set_value(target, value, 0)
 
             if value is None and error is not None:
@@ -1138,6 +1140,8 @@ default_rules: list[Rule] = [
     ),
     Rule("gamma", lambda gamma_arr: gamma_arr[0]),
     Rule("gamma_arr", fiber.gamma_parameter, ["n2", "w0", "A_eff_arr"]),
+    Rule("n2", materials.gas_n2),
+    Rule("n2", lambda: 2.2e-20, priorities=-1),
     # Fiber loss
     Rule("alpha_arr", fiber.compute_capillary_loss),
     Rule("alpha_arr", fiber.load_custom_loss),

src/scgenerator/physics/materials.py

@@ -195,10 +195,29 @@ def non_linear_refractive_index(material_dico, pressure=None, temperature=None):
         ratio = N / N0
     else:
         ratio = 1
-
     return ratio * n2_ref
 
 
+def gas_n2(gas_name: str, pressure: float, temperature: float) -> float:
+    """returns the nonlinear refractive index
+
+    Parameters
+    ----------
+    gas_name : str
+        gas name
+    pressure : float
+        pressure in Pa
+    temperature : float
+        temperature in K
+
+    Returns
+    -------
+    float
+        n2 in m2/W
+    """
+    return non_linear_refractive_index(_utils.load_material_dico(gas_name), pressure, temperature)
+
+
 def adiabadicity(w: np.ndarray, I: float, field: np.ndarray) -> np.ndarray:
     return w * np.sqrt(2 * me * I) / (e * np.abs(field))
 

src/scgenerator/physics/simulate.py

@@ -138,6 +138,7 @@ class RK4IP:
                     self.C_to_A_factor * spectrum, self.dw
                 )
         else:
+            self.logger.debug(f"Using constant step size of {1e6*self.error_ok:.3f}")
             self.conserved_quantity_func = lambda spectrum, h: 0.0
 
     def _setup_sim_parameters(self):

src/scgenerator/plotting.py

@@ -1071,9 +1071,8 @@ def partial_plot(root: os.PathLike):
     spec_list = sorted(
         path.glob(SPEC1_FN.format("*")), key=lambda el: int(re.search("[0-9]+", el.name)[0])
     )
-    print(spec_list)
     raw_values = np.array([load_spectrum(s) for s in spec_list])
-    specs = units.to_log2D(math.abs2(np.fft.fftshift(raw_values)))
+    specs = units.to_log2D(math.abs2(np.fft.fftshift(raw_values, axes=-1)))
     fields = math.abs2(np.fft.ifft(raw_values))
     left.imshow(specs, origin="lower", aspect="auto", vmin=-60, interpolation="nearest")
     right.imshow(fields, origin="lower", aspect="auto", interpolation="nearest")