In situ growth of an ethyl p‐hydroxybenzoate single crystal by the vertical Bridgman technique: a potential nonlinear optical material for third‐harmonic generation

• Published in: Journal of applied crystallography 2021-10, Vol.54 (5), p.1340-1348
• Main Authors: Nayak, Debabrata, Vijayan, N., Kumari, Manju, Kiran, Vashistha, Nikita, Kumar, Mahesh, Pant, R. P.
• Format: Article
• Language: English
• Subjects: Absorptivity; Bridgman method; Crystal defects; Crystal growth; Crystals; Diamond pyramid hardness tests; Emission analysis; Grain boundaries; Harmonic generations; KDP crystals; Laser damage; Lasers; laser‐damage threshold; Mechanical properties; Neodymium lasers; Nonlinear optics; Nonlinear systems; Nonlinearity; optical band gap; Optical materials; Photoluminescence; Photons; Potassium; Potassium phosphates; Pulse repetition rate; Refractivity; Rietveld analysis; Sapphire; Semiconductor lasers; Single crystals; third‐order nonlinearity; vertical Bridgman technique (VBT) for crystal growth; X-ray diffraction; YAG lasers; Yield point
• ISSN: 1600-5767; 0021-8898; 1600-5767
• DOI: 10.1107/S1600576721007913

Optically transparent single crystals of ethyl p‐hydroxybenzoate (EPHB) were successfully grown by the vertical Bridgman technique. The crystalline phase and unit‐cell dimensions were obtained from powder X‐ray diffraction using Rietveld analysis. The presence of defects and grain boundaries was investigated by high‐resolution X‐ray diffraction. The optical quality of the grown single crystal was assessed by UV–Vis and photoluminescent spectroscopies. A blue emission, with a bi‐exponential decay time, was obtained from time‐resolved photoluminescence upon laser excitation at 266 nm. The mechanical strength of the EPHB single crystal was studied by Vickers hardness testing. A decrease in the laser‐damage threshold was observed with a nanosecond Nd:YAG laser source for increased pulse repetition rates. The third‐order nonlinearity, nonlinear absorption coefficient and nonlinear refractive index were measured using the Z‐scan technique with a femtosecond Ti:sapphire laser. The third‐order nonlinear coefficient values for the grown crystal were compared with those of a potassium dihydrogen phosphate single crystal. Good quality single crystals of ethyl p‐hydroxybenzoate (EPHB) were successfully grown by the vertical Bridgman technique. Their properties were investigated to assess the potential applications of EPHB as a nonlinear optical material.