Polymorphism and nonlinear optical activity in organic crystals

Effect of organic dopants on ZTS single crystals

“…It appears that because of the orientational cancellation, the second order susceptibility for SHG vanishes. Although many materials have been identified with higher molecular non-linearities, the attainment of secondorder effects requires favorable alignment of the molecule within the crystal structure [23]. To elaborate, the efficient SHG demands specific molecular alignment of the crystal to be achieved facilitating nonlinearity in the presence of a dopant.…”

Growth and characterization of a new nonlinear optical semiorganic lithium paranitrophenolate trihydrate (NO2–C6H4–OLi·3H2O) single crystal

“…In the recent years there has been growing interest in nonlinear optical inorganic borates, organic MNA, semiorganic LAP and other metalorganic NPNa and borate derivatives crystals owing to their nonlinearity and second harmonic generation properties towards device fabrication [1][2][3][4][5][6][7]. Many applications of nonlinear optics require single crystals in bulk form.…”

Concomitant Polymorphs

“…This goal has led to the variation of crystallization conditions in the search for crystals of potential SHG materials, and has resulted in the discovery of polymorphic systems, [96] as well as the development of a number of strategies for obtaining structures with the required symmetry properties. [97] Recently Pan et al reported many crystallization studies on 23, which is at least trimorphic, the three modifications being easily recognized by habit and color: form I, red greenish plates (P2 1 /n); form II, red orange prisms (Pna2 1 ); form III, black needles (P2 1 /n).…”