All-optical induction of noncentrosymmetry in a transparent nonlinear polymer rod.
What is believed to be the first evidence of an all-optical orientation of a highly transparent polymer is presented. The samples are bulk rods of poly(methyl methacrylate) grafted with paranitroaniline (PNA) obtained by use of copolymerization of methyl methacrylate (MMA) monomers mixed with grafted MMA-PNA monomers. Bulk samples were obtained after molding and polishing of the copolymer with standard techniques. Experiments show that the photoinduced second-order(1) susceptibility chi((2)) may occur through molecular reorientation following selective polar excitation of the nonlinear chromophores by simultaneous two- and three-photon absorption on the same electronic level.
Fiorini
C
C
Charra
F
F
Raimond
P
P
Lorin
A
A
Nunzi
J M
JM