Optimisation of a low cost SLM for diffraction efficiency and ghost order suppression R. Bowman, V. D’Ambrosio, E. Rubino, O. Jedrkiewicz, P. Di Trapani and M.J. Padgett Eur. Phys. J. Special Topics, 199 (2011) 149-158 Published online: 07 December 2011 DOI: 10.1140/epjst/e2011-01510-4