FIG. 3: Polarization dependence of transient reflectivity variation in 1T-TiSe$_{2}$ measured at 3 K (a) and 1T-TaS$_{2}$ measured at 12 K (b). The height of each peaks are plotted in the figure (c) and (d) as function of polarization angle E$_{pol}$ . The pump pulse wavelength is 1160 nm and the power is 150 µ W. The probe pulse is 800 nm, 80 µ W. 11