An organic-inorganic crystal for blue SHG: crystal growth and quadratic optical effect of 2-amino-5-nitropyridinium chloride

The effective quadratic coefficients 2-amino-5-nitropyridinium chloride (2A5NPCl) are measured by phase matched second harmonic generation. 2A5NPCl is an interesting material for quadratic nonlinear optics due to the quasi-optimized arrangement of 2A5NP units in herringbone motifs and the high density of nonlinear 2-amino-5-nitropyridinium chromophore per unit volume. The maximum effective coefficient is obtained as 9.7 pm/V at 1320 nm. Since 2A5NPCl crystal is transparent from 410 to 1650 nm, sum frequency generation is also carried out with incident beams of 1320 and 660 nm. In this study, 11% conversion efficiency from 660 to 440 nm is obtained for 1.6 mm interaction length. (C) 1999 Elsevier Science B.V. All rights reserved.