  We investigate the two-particle interferometry for the particle-emitting
sources which undergo the first-order phase transition from the quark-gluon
plasma with a finite baryon chemical potential to hadron resonance gas. The
effects of source expansion, lifetime, and particle absorption on the
transverse interferometry radii $R_{\rm out}$ and $R_{\rm side}$ are examined.
We find that the emission durations of the particles become large when the
system is initially located at the boundary between the mixed phase and the
quark-gluon plasma. In this case, the difference between the radii $R_{\rm
out}$ and $R_{\rm side}$ increases with the transverse momentum of the particle
pair significantly. The ratio of $\sqrt{R_{\rm out}^2 -R_{\rm side}^2}$ to the
transverse velocity of the pair is an observable for the enhancement of the
emission duration.
