Detection of the Galaxy Lensing the Doubly-imaged Quasar SBS 1520+530
  H band observations with a spatial resolution of 0.15" carried out with the Canada-France-Hawaii Telescope adaptive optics system show a galaxy between the components of the double BAL quasar SBS 1520+530, thereby confirming this system as a gravitational lens. The galaxy is located 0.40" from the fainter of the two QSO images and is offset 0.12" from the line joining them. The H magnitude of the lensing galaxy is ~1 mag fainter than expected from the velocity dispersion derived for the lensing galaxy were it at z = 0.71 or z = 0.81, the redshifts of the two absorption line systems. 
David Crampton, P.L. Schechter, J.-L. Beuzit