Spectral, optical, etching, second harmonic generation (SHG) and laser damage threshold studies of nonlinear optical crystals of l-Histidine bromide

Abstract

Nonlinear optical (NLO) materials find broad applications in optical data storage, lasers, optical signal processing, second harmonic generation, etc. Though a large number of nonlinear optical materials are available, their applications are limited due to physical and chemical properties.Since the nonlinear optical crystals of amino acids contain a proton donor carboxyl acid (COOH) group and the proton acceptor amino (NH2) group, they are considered as the apt materials for NLO applications. In the present work, good quality crystals of l-Histidine bromide were grown by using slow evaporation technique. The FTIR spectral analysis reveals the presence of different vibrational bands of l-Histidine Bromide.The optical characteristics were assessed by UV–vis analysis, which shows that the crystals have a transmission in the visible range.The etching studies were performed on the crystals, which shows that the crystal does not undergo considerable deformation under the action of solvents. The refractive index of the l-Histidine Bromide crystal was found by Brewster's angle method as 1.516. The Second harmonic generation studies and laser damage threshold studies reveal that crystals have comparable SHG conversion efficiency and high laser damage threshold value to that of the standard KDP crystal, thus making the crystals suitable for applications.