  We determined the optical conductivity of Bi(2)Sr(2-x)La(x)CuO(6) at dopings
covering the phase diagram from the underdoped to the overdoped regimes. The
frequency dependent scattering rate shows a pseudogap extending into the
overdoped regime. We found that the effective mass enhancement calculated from
the optical conductivity is constant throughout the phase diagram. Conversely,
the effective optical charge density varies almost linearly with doping. Our
results suggest that the low frequency electrodynamics of
Bi(2)Sr(2-x)La(x)CuO(6) is not strongly affected by the long range Mott
transition.
