Update docs/source/run/parameters.rst

Co-authored-by: Maxence Thévenet <[email protected]>

docs/source/run/parameters.rst

@@ -914,7 +914,7 @@ Parameters starting with ``lasers.`` apply to all laser pulses, parameters start
           Spatial chirp at focus.
 
       * ``<laser name>.phi2`` (`float`) optional (default `pi/2`)
-          The amount of temporal chirp :math:`\phi^{(2)}` at focus (in the lab frame).
+          Temporal chirp :math:`\phi^{(2)}` at focus.
           Namely, a wave packet centered on the frequency :math:`(\omega_0 + \delta \omega)` will reach its peak intensity at :math:`z(\delta \omega) = z_0 - c \phi^{(2)} \, \delta \omega`.
           Thus, a positive :math:`\phi^{(2)}` corresponds to positive chirp, i.e., red part of the spectrum in the front of the pulse and blue part of the spectrum in the back.
           More specifically, the electric field in the focal plane is of the form: