Bulk crystal growth, crystalline perfection and optical homogeneities of 2AP4N single crystals for second and third order frequency conversion and terahertz (THz) device applications

Abstract

Bulk size organic 2AP4N single crystals were grown by a point seed rotation technique using methanol solvent. The lattice dimensions of the grown crystal and their various crystalline planes have been analyzed by XRD measurement and also the lattice strain was calculated. The lattice perfection was examined by HRXRD and found to be extremely good. The optical transparency and cut-off value of the grown crystal were analyzed by the UV–Vis NIR measurement. The crystalline homogeneity has been confirmed by the birefringence and Mach-Zehnder interferometry techniques. The SHG measurement has been carried out with different particles. The refractive indices of grown crystal have been measured in different wavelengths by prism coupling technique and the Sellmeier's co-efficient has been calculated. The Type-I and Type-II phase-matching angles were determined and the crystal was cut along the phase-matching angles. The third order nonlinear optical parameters were analyzed by Z-scan technique. In addition, the crystal shows potential to generate pulsed Terahertz (THz) radiation by optical rectification using 800 nm wavelength at 140 fs, obtained from Ti: Sapphire Laser. The generated THz spectrum is extended up to 3.0 THz. The maximum conversion efficiency of the generated signal is of the order of 0.64 × 10 −5 %. •Optically high quality with bulk size single crystal was grown by seed rotation technique •The grown crystal has high optical homogeneities and crystalline perfection •SHG efficiency is 4.5 times that of KDP material •Type-I and Type-II phase matching elements have been made •Third-order nonlinear susceptibility ‘ χ (3) ’ is 8.68 × 10 −8 esu. •The maximum conversion efficiency of the generated THz signal is 0.64 × 10 −5 %.