Remarkable enhancement in crystalline perfection, second harmonic generation efficiency, optical transparency, and laser damage threshold in potassium dihydrogen phosphate crystals by L-threonine doping

Abstract

Effect of L-threonine ͑LT͒ doping on crystalline perfection, second harmonic generation ͑SHG͒ efficiency, optical transparency, and laser damage threshold ͑LDT͒ in potassium dihydrogen phosphate ͑KDP͒ crystals grown by slow evaporation solution technique ͑SEST͒ has been investigated. The influence of doping on growth rate and morphology of the grown crystals has also been studied. Powder x-ray diffraction data confirms the crystal structure of KDP and shows a systematic variation in intensity of diffraction peaks in correlation with morphology due to varying LT concentration. No extra phase formation was observed which is further confirmed by Fourier transform Raman ͑FT-Raman͒ studies. High-resolution x-ray diffraction curves indicate that crystalline perfection has been improved to a great extent at low concentrations with a maximum perfection at 1 mol % doping. At higher concentrations ͑5 to 10 mol %͒, it is slightly reduced due to excess incorporation of dopants at the interstitial sites of the crystalline matrix. LDT has been increased considerably with increase in doping concentration, whereas SHG efficiency was found to be maximum at 1 mol % in correlation with crystalline. The optical transparency for doped crystals has been increased as compared to that of pure KDP with a maximum value at 1 mol % doping.

Effect of necking on Czochralski-grown LiF crystals and its influence on crystalline perfection and the correlated physical properties

“…However, the sample preparation is rather tedious, and because of the presence of artefacts one cannot really detect the actual d-parameter changes. It may also be mentioned here that, even in doped crystals, wherein the dopants occupy the interstitial sites, no change in the overall lattice parameter could be found by standard powder X-ray diffraction analysis (wherein the positions of many peaks are taken into account for latticeparameter determination through various refinement processes), as again the strain developed by such defects is very localized and could not change the overall lattice parameter (Kushwaha et al, 2010;Bhagavannarayana et al, 2008). However, while attributing the asymmetry of an RC to point defects, doubts may arise as to whether the observed asymmetry is due to the probable mosaicity of the crystal; in this case the micro-or nano-sized crystallites or mosaic blocks may have a preferred orientation (if they are oriented randomly, one cannot get any asymmetry), which could be misoriented by only a few arcseconds from the main crystal block.…”

Brilliant green dye added zinc(tris) thiourea sulphate monocrystal growth with enhanced crystalline perfection, optical, photoluminescence and mechanical properties

“…Several key properties such as morphology, growth rate, crystalline perfection, optical transparency, band gap, second harmonic generation (SHG) efficiency, laser damage threshold (LDT) are found to be enhanced/change due to some additives or dopants in ZTS as well as many other crystals [9,[20][21][22][23][24][25]. Single crystal growth with dye doping has been attracted to many researchers and scientist due to their possible applications in solid state lasers as well as many other applications [26][27][28][29][30][31][32][33][34][35][36][37][38]. Recently Benedict et al, has studied the dyeing processes in crystals and designed simple sulfate, phosphate and carboxylate salts single crystals and grown in solution [39].…”

Organic Triplet Sensitizer Library Derived from a Single Chromophore (BODIPY) with Long-Lived Triplet Excited State for Triplet–Triplet Annihilation Based Upconversion

“…1À3 A few techniques are available for upconversion, e.g., by using two-photon absorption (TPA) dyes, 4,5 nonlinear optical crystals, such as potassium dihydrogen phosphate (KDP), 6 etc. However, these techniques suffer from some fundamental drawbacks.…”