Enhanced optical, mechanical, photoacoustic and third-order nonlinear property of pure and crystal violet (CV) dye incorporated anthracene crystal: an efficacious material for nonlinear optical applications

Analysis of the growth and physicochemical properties of the newly developed stilbazolium derivative 4-N,N-dimethylamino-4-N-methyl stilbazolium 2-formyl benzene sulfonate (DSFS) single crystal: an effective material for nonlinear optical applications

“…The third-order susceptibility value of the title ionic crystal is compared with a few other stilbazolium derivatives and organic centrosymmetric crystals, and the comparison is tabulated in Table 4. These comparison results indicate that the title DSFS crystal possesses a comparatively large c (3) value.…”

“…From the following equation, it is possible to calculate the disorder in the system as a function of α , which corresponds to the transition between the localized states and the extended state of the conduction and valence bands, through a parameter known as the Urbach energy ( E u ). 41,44 where h , ν , α 0 , and E u represent Planck's constant, the incident frequency radiation, a constant and Urbach energy, respectively. The width of the elongated tail of the localized states in the forbidden electronic band gap (Urbach energy or band tail energy) was obtained by plotting a graph between the ln of the absorption coefficient α vs. hν .…”

“…If the laser's operating wavelength is beyond 1530 nm, the transmittance curve in the closed aperture method will disappear. 60 The calculated values of the nonlinear refractive index NLRI (n 2 ), nonlinear absorption coefficient NLAC (b) and third-order susceptibility (c (3) ) are found to be 4.6494 Â 10 −11 m 2 W −1 , 2.203 Â 10 −4 m W −1 and 1.573 Â 10 −7 esu, respectively. The third-order susceptibility value of the title ionic crystal is compared with a few other stilbazolium derivatives and organic centrosymmetric crystals, and the comparison is tabulated in Table 4.…”

“…The real and imaginary parts of c (3) can be directly derived from the nonlinear refractive index and nonlinear coefficient of absorption with the following equations: 59 Rec ð3Þ ðesuÞ ¼…”

“…The study of organic NLO crystals is a scholastic area of interest due to their ample applications in different domains, such as signal processing, electro-optic modulators, telecommunication, optical switches, deep UV light, high-density data storage and display technologies. [1][2][3][4][5][6][7][8] The presence of delocalized p-electrons, donor and acceptor moieties, hydrogen bonds and weak Van der Waals forces induce high non-linearity in the organic crystals compared to its counterpart, inorganic materials. 9 Also, tunability of the structure, high laser damage threshold, ultra-fast response and the signicant electro-optic coefficient are the added advantages of the organic materials.…”