Interesting concept Aadil,from your reply as i understand you want to realize wDM with Spatial modes generely refered as SDM.As far as generation of lp modes is concerned then you can set array in CW LASEr and yes MZM modulate multiple modes.But i am little confused about sine wave . Here i have attached a link ,let me know if it helpshttp://www.ijert.org/view-pdf/13595/implementation-and-analysis-of-lp-modes-over-owc-link-using-different-pulse-shapes