Additionally negative phase difference can be provided to convert {HEAD ~ linear polarized light} into left handed circling polarized light or {TAIL ~ elliptic polarized light} 
into
Additionally negative phase difference can be provided to convert { HEAD ~ linear polarized light } into left handed circling polarized light or { TAIL ~ elliptic polarized light }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL