http://www.sciencedirect.com/science/article/pii/S0030402612008935
https://www.osapublishing.org/oe/abstract.cfm?uri=oe-15-20-13282
https://www.osapublishing.org/oe/abstract.cfm?uri=oe-18-20-20651
http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=4785281&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D4785281
http://www.ncbi.nlm.nih.gov/pubmed/2245347
Regards