Interferometry with Vortices (2012) by P. Senthilkumaran, Jan Masajada, and Shunichi Sato
Robust
interferometer
for the routing of light beams carrying orbital angular
momentum (2011) by Martin P J Lavery, Angela Dudley,
Andrew Forbes, Johannes Courtial and Miles J Padgett
Interferometric optical vortex array generator (2007) by Sunil Vyas and P. Senthilkumarans