In particular, Bessel beams are {HEAD ~ light beams} having {TAIL ~ properties} most similar to those of LG beams, however, currently known generating techniques can only generate approximate Bessel beams 
having
In particular , Bessel beams are { HEAD ~ light beams } having { TAIL ~ properties } most similar to those of LG beams , however , currently known generating techniques can only generate approximate Bessel beams
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH