We compute the optical conductivity perpendicular to the conducting chains
in the spin density wave phase in Bechgaard salts (TMTSF)(2)X with X=PF6 an
d ClO4. We assume that the quasi-particle damping is entirely due to impuri
ty scattering, and neglect the effect of imperfect nesting for simplicity.
The present theory appears to describe the recent data from (TMTSF)(2)PF6 a
nd (TMTSF)(2)ClO4 reasonably well.