Laser induced optical and microscopic studies of salicylic acid influenced KH₂PO₄ crystal for photonic device applications

Abstract

The present communication is aimed to explore the characteristic properties of salicylic acid (SA) doped potassium dihydrogen orthophosphate (KDOP) crystal. The single SA doped KDOP crystal with optimum dimension of 10 × 08 × 04 mm³ has been grown from solution by slow evaporation at ambient temperature. The single crystal X-ray diffraction analysis has been employed to determine the structure and cell parameters of grown crystal. The Z-scan studies have been carried out at 632.8 nm to ascertain the influential third-order non-linear optical (TONLO) nature of SA doped KDOP crystal. The Z-scan transmittance data have been used to determine the magnitude of TONLO susceptibility (χ³), absorption coefficient (β) and refractive index (n₂) of SA doped KDOP crystal. For grown crystal, the surface damage due to exposure of high intensity of Nd:YAG laser operating at 1064 nm has been determined and found of order MW cm⁻². The growth tendency, etch pattern and surface quality of grown SA doped KDOP crystal has been investigated by means of etching studies. The thermal response of grown crystal has been examined by differential thermal analysis employed in the range of 23–800°C. The hardness number of SA doped KDOP crystal has been investigated by means of Vickers microhardness study by applying different load ranging from 25 to 100 gm. The work hardening index and elastic stiffness coefficient have been evaluated using the hardness data. The nature of photoconductivity exhibited by grown crystal has been determined in voltage range of 10–100 V.

Highlights

•	Z-scan analysis revealed negative non-linear refraction and reverse saturable absorption effect in SA-KDOP crystal.
•	The laser damage threshold of SA-KDOP crystal at 1064 nm is found to be 274·74 MWcm−2.
•	SA-KDOP crystal exhibited positive photoconducting nature within 10–100 V.
•	The dopant SA facilitated large enhancement in hardness parameters of KDOP crystal.
•	Etching and thermal analysis has been performed.

Keywords:

• Photonic crystal
• electrical studies
• microscopic studies
• thermal study
• Z-scan study

Acknowledgement

Author Mohd Anis highly appreciates the support by Dr. M.S. Pandian (SSN College of Engineering, Chennai, India) and acknowledges the award of Maulana Azad National Fellowship (F1-17.1/2015-16/MANF-2015-17-MAH-68193).