  We show the emergence of light localization in arrays of coupled optical
waveguides with randomness only in the imaginary part of their permittivity and
develop a one-parameter scaling theory for the normalized participation number
of the Floquet-Bloch modes. This localization introduces a new length scale in
the decay of the autocorrelation function of a paraxial beam propagation. Our
results are relevant to a vast family of systems with randomness in the
dissipative part of their impedance spatial profile.
