diff --git a/pyproject.toml b/pyproject.toml
index 8a100b7..bd90388 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "scgenerator"
-version = "0.4.2"
+version = "0.4.3"
 description = "Simulate nonlinear pulse propagation in optical fibers"
 readme = "README.md"
 authors = [{ name = "Benoit Sierro", email = "benoit.sierro@iap.unibe.ch" }]
diff --git a/src/scgenerator/noise.py b/src/scgenerator/noise.py
index b249172..a321bac 100644
--- a/src/scgenerator/noise.py
+++ b/src/scgenerator/noise.py
@@ -143,7 +143,7 @@ class NoiseMeasurement:
         return freq[left:], psd[left:]
 
     def sample_spectrum(
-        self, nf: int, dt: float | None = None, log_mode: bool = False
+        self, nf: int, dt: float | None = None, log_mode: bool = False, left: float | None = None
     ) -> tuple[np.ndarray, np.ndarray]:
         """
         sample an amplitude spectrum with nt points. The corresponding sample spacing in the time
@@ -156,6 +156,9 @@ class NoiseMeasurement:
         dt : float | None, optional
             if given, freq will only be sampled up to 0.5/dt. if that value is higher than the
             max of freq, an exception is raised.
+        left : float | None, optional
+            extend current PSD to the lower frequency range by assuming a constant value of `left`.
+            if None (default), extends with the last value
         log_mode : bool, optional
             sample on a log-log scale rather than on a linear scale, by default False
         """
@@ -171,19 +174,24 @@ class NoiseMeasurement:
         if log_mode:
             interp = np.zeros_like(f)
             ind = self.freq > 0
+            if left is not None and left <= 0:
+                raise ValueError(f"value {left!r} for `left` in log mode is invalid")
+            elif left is None:
+                left = self.psd[ind][0]
             interp[1:] = np.exp(
                 np.interp(
                     np.log(f[1:]),
                     np.log(self.freq[ind]),
                     np.log(self.psd[ind]),
-                    left=np.log(self.psd[ind][0]),
+                    left=np.log(left),
                     right=np.log(self.psd[ind][-1]),
                 )
             )
             if self.freq[0] == 0:
                 interp[0] = self.psd[0]
         else:
-            interp = np.interp(f, self.freq, self.psd, left=self.psd[0], right=self.psd[-1])
+            left = left if left is not None else self.psd[0]
+            interp = np.interp(f, self.freq, self.psd, left=left, right=self.psd[-1])
         return f, interp
 
     def resampled(self, nf: int, dt: float | None = None, log_mode: bool = False) -> Self:
@@ -211,7 +219,7 @@ class NoiseMeasurement:
             sample on a log-log scale rather than on a linear scale, by default False
         """
 
-        freq, amp = self.sample_spectrum(nf, dt, log_mode)
+        freq, amp = self.sample_spectrum(nf, dt, log_mode, left=0)
         fs = freq[-1] * 2
 
         if nf % 2: