The authors have developed an interferometer requiring only minimal angular alignment for the routing of beams carrying orbital angular momentum. The Mach–Zehnder interferometer contains a Dove prism in each arm where each has a mirror plane around which the transverse phase profile is inverted. The authors' consequence of the inversions is that the interferometer needs no alignment. Instead the interferometer defines a unique axis about which the input beam must be coupled. Experimental results are presented for the fringe contrast, reaching a maximum value of 93±1%.
Reference:
Lavery, MPJ, Dudley, A.L., Forbes, A et al. 2011. Robust interferometer for the routing of light beams carrying orbital angular momentum. New Journal of Physics, Vol 13, pp 7
Lavery, M., Dudley, A. L., Forbes, A., Courtial, J., & Padgett, M. (2011). Robust interferometer for the routing of light beams carrying orbital angular momentum. http://hdl.handle.net/10204/5197
Lavery, MPJ, Angela L Dudley, A Forbes, J Courtial, and MJ Padgett "Robust interferometer for the routing of light beams carrying orbital angular momentum." (2011) http://hdl.handle.net/10204/5197
Lavery M, Dudley AL, Forbes A, Courtial J, Padgett M. Robust interferometer for the routing of light beams carrying orbital angular momentum. 2011; http://hdl.handle.net/10204/5197.