fs

main.tex

@@ -423,9 +423,9 @@ free carrier diffusion is neglected during and shortly after the laser
 excitation \cite{Van1987, Sokolowski2000}. In particular, from the
 Einstein formula $D = k_B T_e \tau/m^*$ $\approx$ (1-2)10$^5$ m/s
 (k$_B$ is the Boltzmann constant, T$_e$ is the electron temperature,
-$\tau$=1~fs is the collision time, $m^*$ = 0.18$m_e$ is the effective
+$\tau$=1~\textit{fs} is the collision time, $m^*$ = 0.18$m_e$ is the effective
 mass), where T$_e$ $\approx$ 2*10$^4$~K for N$_e$ close to N$_cr$. It
-means that during the pulse duration ($\approx$ 50~fs) the diffusion
+means that during the pulse duration ($\approx$ 50~\textit{fs}) the diffusion
 length will be around 5--10~nm for N$_e$ close to N$_cr$.
 
 \begin{figure}[ht!] 
@@ -597,9 +597,9 @@ license.
  whereas electric one (\textit{a1}) has $Q \approx$4. The larger
  particle supporting magnetic quadrupole resonance (\textit{b2})
  demonstrates \textit{Q} $\approx$ 40. As soon as the electromagnetic
- wave period at $\lambda$~=~800~nm is 2.6~fs, we need about 10~fs
- pulse to pump the electric dipole, 20~fs for the magnetic dipole, and
- about 100~fs for the magnetic quadrupole.
+ wave period at $\lambda$~=~800~nm is 2.6~\textit{fs}, we need about 10~\textit{fs}
+ pulse to pump the electric dipole, 20~\textit{fs} for the magnetic dipole, and
+ about 100~\textit{fs} for the magnetic quadrupole.
 
  According to these estimations, the first optical cycles taking place
  on few-femtosecond scale result in the excitation of the
@@ -620,7 +620,7 @@ license.
  is still not high enough to affect significantly optical properties
  of the Si NP.
 
- A number of optical cycles ($>$10 or $t>$25~fs) is necessary to
+ A number of optical cycles ($>$10 or $t>$25~\textit{fs}) is necessary to
  achieve the stationary intensity pattern corresponding to the
  Mie-based intensity distribution at the \textit{'Stage $3$'} (see
  Fig.~\ref{fig3}). The EHP density are still relatively not high to