Second-order nonlinear-optical properties of donor- and acceptor-substituted aromatic compounds

Enhanced second-harmonic response and stability of corona-poled guest?host polycarbonate thin films

“…For this estimation of d33, the NLO chromophore is considered to be a one-dimensional molecule with the molecular axis in the z-direction so that only [3~=~ is non-zero; therefore, the [~-values [16] of 125 x 10-3o esu for DR1 and 103 x 10-3o esu for DO3 were taken for [3~. Appropriate local field factors for the optical field, f~, are Lorentz-Lorenz type, (n2o + 2)/3, where n, is the refractive index at radian frequency co. For DR1/PC, n, = 1.607 and nZoj = 1.652, and for DO3/PC, n~o= 1.609 and rt2o ~ = 1.655.…”

Analysis on linear and nonlinear optical properties of two Bisphenols with DFT approach: A comparative study

“…These components lead to the large values for bx 2 and bz 2 ( Table 5) [20] where there is a possibility of loss of transparency in the visible region [21] which leads to the ineffectiveness of the material in NLO applications. This tendency towards 1DCT could also be evidenced from the parameter q which is the ratio of octupolar over dipolar contributions.…”

Quadratic hyperpolarizabilities of nitro-substituted pseudo-linear dye molecules with ethylenic and azo bridges

“…The following unconventional shorthand notation will be used to denote these dye molecules substituted by electron donor (D) and acceptor ( It is well known that the DCSHG experimental data is strongly dependent on solvent (medium) polarity, and the data measured in polar media tend to be larger than those in nonpolar media [12,43,441 -0Me < -NH, < -"Me, < -NEt,. (12) As described in the previous section, the Hammett substituent constant a: has been used to describe the relative efficacy of substituents in terms of their ability to attact or donate n--electrons.…”

“…The n--electron-transfer efficiency is dependent on the electronic nature of the long m-conjugated systems, especially on that of the n--electron bridges. Singer et al measured the nonresonant p values of a series of organic n--conjugated molecules, including some stilbene, imine, and azobenzene derivatives, using dc-induced second-harmonic generation (DCSHG) [12]. They reported that the stilbene derivatives, which contain ethylenic ( -CH=CH -1 bridges, are somewhat better for constructing high-p molecules than the imine derivatives containing imino (-CH = N -) bridges.…”