Radially polarized annular beam generated through a second-harmonic-generation process.
A radially polarized beam with an annular intensity pattern was generated through a second-harmonic-generation process by focusing an azimuthally polarized Ti:sapphire pulsed laser beam to a c-cut beta-barium borate (BBO) crystal. The annular intensity pattern of the second-harmonic wave had a nearly sixfold symmetry as a result of the nonlinear susceptibility tensor of the BBO crystal. The width of the annulus was as narrow as less than 1/40th of its radius.
Sato
Shunichi
S
Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1,Sendai 980-8577, Japan. sato@tagen.tohoku.ac.jp
Kozawa
Yuichi
Y