Laser Induced Damage Threshold Study Research Articles

Laser-induced damage threshold study on TiO2/SiO2 multilayer reflective coatings

Laser-induced damage threshold (LIDT) is a key parameter in high power laser systems. Highly reflective mirrors are made by the combination of high index and low index dielectric thin films of materials, usually oxides, having high damage threshold. The aim of the present investigation was to study the effect of multilayers on LIDT for a combination of high and low index material films with the increase in the number of layers. Firstly, we chose a combination of relatively high damage threshold high index (H) and low index (L) oxide materials, like TiO2 and SiO2. Then, we chose five reflective samples with increasing the number of layers starting with a TiO2 single quarter wave optical thick (QWOT) layer, three-QWOT layer (HL)1H, five-QWOT layer (HL)2H, seven-all QWOT layer (HL)3H and seven-layer (HL)2H 1.6L0.4H with upper two non-quarter layers for sample preparation using electron beam deposition. It has been found that LIDT measured at 1064 nm for single layer is large (2.09 J/cm2), decreases for three layers and remains nearly constant (1.51 J/cm2) as the number of multilayers increases further. When LIDT is measured at 532 nm, LIDT of the single layer and multilayers remains almost the same. However, in case of top two layers made of non-QWOT in seven-layer design the LIDT of the samples in both the cases improved.

Synthesis,Crystal Growth Spectral and Optical Studies on Amino Acid Based New Novel NLO Single Crystal: L-Isoleucinium Phthalate (LIP)

Good quality colourless transparent nonlinear optical single crystals of L-Isoluecinium phthalate (LIP) was grown successfully by slow evaporation solution growth method from aqua solution at room temperature. Single crystals of LIP of dimensions 15mm x 8mm x 5mm were harvested after 50 days. The lattice parameter of grown crystal was studied by single crystal X- ray diffraction analysis and it was confirmed that the grown crystals belong to monoclinic crystal system with noncentrosymmetric space group of C2. Fourier transform infrared spectroscopic (FT-IR) studies was carried out using Jasco FT/IR 6300 Fourier transform infrared spectrometer by ATR method in the range of 400 – 4000 cm-1and it has been used to confirm the vibrational frequencies of various functional groups present in the crystal. Laser induced damage threshold study was carried using Q-Switced Nd: YAG laser and the laser power with the threshold value of 0.323 GW/cm2 also calculated. The UV-Vis-NIR spectroscopic study confirms that the crystal has good optical transparency and the cut off wavelength was found to be 300 nm. The band gap of the grown crystal was determined from the Tauc plot. The nonlinear optical property was confirmed by Kurtz Perry powder technique and it was compared with the standard pure potassium dihydrogen phosphate (KDP) crystals. In addition, a photoluminescence analysis was carried out for LIP crystal

Growth, structural, linear, nonlinear optical and laser induced damage threshold studies of an organic compound: 2-Amino pyridinium-4-hydroxy benzoate

Single crystals of 2-Amino pyridinium-4-hydroxy benzoate (2AP4HB) have been successfully grown by controlled slow evaporation technique. The title compound was synthesized and single crystals were harvested utilizing methanol as a solvent. The crystalline structure and crystal phase studies were carried out by single crystal and powder X-ray diffraction techniques respectively. UV–Vis transmission plot was traced and band gap value has been calculated for the title compound. Laser induced damage threshold (LIDT) analysis of 2AP4HB single crystal has been performed employing 1064 nm wavelength Nd:YAG laser. Third order nonlinear optical (NLO) efficiency of grown 2AP4HP single crystals was probed using Z-Scan technique. Optical limiting study of 2AP4HB was carried out using continuous wave (cw) Nd:YAG laser to reveal its saturable absorption behavior and self-defocusing effect.

Structural, optical, dielectric, second and third-order nonlinear properties of new semiorganic crystal: Sodium (bis) boro succinate

A new semiorganic nonlinear optical crystal Sodium (bis) boro succinate (SBBS) [Na2 (C4H4O4) (H3BO3)(H2O)4]·H3BO3 was grown from aqueous solution by slow evaporation growth technique. Single crystal X-ray diffraction analysis revealed that the crystal belongs to monoclinic crystal system with space group of P21/n. The crystalline nature of SBBS crystal was analyzed by Powder X-ray diffraction. The morphology and growth axis of grown crystal were investigated. The functional groups present in the compound were confirmed by FTIR and FT-Raman spectroscopy techniques. The cut-off wavelength, optical transmission and band gap energy of the grown crystal were analysed by UV–Visible spectral studies. Electrical behaviour of SBBS crystal was analysed by dielectric studies. Laser induced damage threshold study was carried out for SBBS crystal using Nd:YAG laser. Second harmonic generation and relation between particle sizes with respect to generated output were investigated by Kurtz-Perry powder technique. Third order nonlinear properties of SBBS crystal were analyzed by Z-scan method and the corresponding nonlinear refractive index, absorption coefficient and optical susceptibility were calculated.

Studies on the crystal growth and optical properties of novel organic material: o-Phenylenediaminium bis-hydrogen phosphonate

o-Phenylenediaminium bis-hydrogen phosphonate (P2HP) was synthesized and single crystals were grown by slow evaporation method. The crystal structure, crystalline perfection and morphology of P2HP were studied and interpreted from XRD studies and WinXMorph program respectively. UV–Visible transmittance was performed to estimate the transmittance and bandgap energy. Laser induced damage threshold study was performed for the grown crystal. Third order nonlinear optical parameters of P2HP crystal was estimated by Z-scan test.

Synthesis, growth, optical, spectral, thermal and dielectric studies of a new nonlinear optical material : l-proline 2,4-dichlorobenzoic acid single crystal

Good quality single crystals of organic nonlinear optical material l-proline 2,4-dichlorobenzoic acid (LPDCBA) were synthesized and grown by slow evaporation technique. The lattice parameters and space group were determined using single crystal XRD analysis. The optical absorbance and the lower cut-off wavelength of the LPDCBA were identified by UV–VIS–NIR studies. The modes of vibrations of different molecular groups present in the sample were identified by the FTIR spectral analysis. Dielectric measurement of LPDCBA were carried out at different frequencies. Thermal stability of LPDCBA were determined by TGA/DTA measurements. Laser induced damage threshold study was carried out for the grown crystal using Nd:YAG laser. The second harmonic generation efficiency were found to be 1.66 times greater than that of KDP.

Bulk crystal growth and nonlinear optical characterization of semiorganic single crystal: Cadmium (II) dibromide l - Proline monohydrate

Single crystal of a novel metal organic nonlinear optical (NLO) cadmium (II) dibromide l - proline monohydrate (CBLPM) of size 7 × 7 × 5 mm3 was grown from slow evaporation technique. Single crystal X – ray diffraction analysis reveals that the crystal belongs to orthorhombic system with lattice parameters a = 10.1891 (8) Å, b = 13.4961 (11) Å, c = 7.4491 (5) Å and space group P212121. The powder X – ray diffraction pattern of CBLPM was recorded and the X – ray diffraction peaks were indexed. The various functional groups of CBLPM were identified by the FT – IR and FT – Raman spectral analyses. The optical transmittance window and lower cut off wavelength of CBLPM were identified from UV – Vis – NIR studies. The mechanical strength of the grown crystal was estimated using Vickers microhardness test. Dielectric constant and dielectric loss measurements were carried out at different temperatures in the frequency range of 50 Hz - 2 MHz. The photoluminescence spectrum was recorded in the wavelength range 200–400 nm and the estimated optical band gap was ∼4.1 eV. Etching studies were carried out for different etching time. Thermal stability of CBLPM was determined using thermogravimetric analysis. Laser induced damage threshold study was carried out for the grown crystal using Nd:YAG laser. Size dependent second harmonic generation efficiency of the grown crystal was determined by Kurtz and Perry powder technique with different particle size using Nd:YAG laser with wavelength 1064 nm. Second harmonic generation efficiency of the powdered CBLPM crystal was ∼2.3 times that of potassium dihydrogen orthophosphate.

Bulk crystal growth, thermal and optical characterization of Piperazinium l-tartrate single crystals

An organic nonlinear optical single crystal of Piperazinium l-tartrate (PPLT) was grown from aqueous solution by a slow evaporation solution growth technique. Single crystal X-ray diffraction study revealed that the PPLT crystal belongs to monoclinic system with space group of P21. UV–vis–NIR study showed that the PPLT crystal has a wide transmission window with low near-UV cut-off wavelength at 231nm. The laser induced damage threshold study revealed that the grown PPLT crystal has an excellent resistance to laser radiation with a high laser damage threshold value up to 8.7GW/cm2. Thermogravimetric and differential thermal studies showed that the PPLT crystal is thermally stable up to 505K. The relative SHG efficiency of PPLT was found to be 0.7 times that of KDP crystal.

Crystal growth, spectral, structural and optical studies of π-conjugated stilbazolium crystal: 4-Bromobenzaldehyde-4′-N′-methylstilbazolium tosylate

Nonlinear optical (NLO) organic compound, 4-bromobenzaldehyde-4′-N′-methylstilbazolium tosylate was synthesized by reflux method. The formation of molecular complex was confirmed from 1H NMR, FT-IR and FT-Raman spectral analyses. The single crystals were grown by slow evaporation solution growth method and the crystal structure and atomic packing of grown crystal was identified. The morphology and growth axis of grown crystal were determined. The crystal perfection was analyzed using high resolution X-ray diffraction study on (001) plane. Thermal stability, decomposition stages and melting point of the grown crystal were analyzed. The optical absorption coefficient (α) and energy band gap (Eg) of the crystal were determined using UV–visible absorption studies. Second harmonic generation efficiency of the grown crystal was examined by Kurtz powder method with different particle size using 1064nm laser. Laser induced damage threshold study was carried out for the grown crystal using Nd:YAG laser.

Growth, linear and nonlinear optical and, laser damage threshold studies of organometallic crystal of MnHg(SCN) 4

Single crystals of bimetallic MnHg(SCN) 4 (abbreviated as MMTC) are grown by slow cooling method and the second and third order optical nonlinearities are investigated by Kurtz and Perry powder SHG test and single beam Z-scan technique respectively. The influences of SCN ligand in modifying the NLO properties are discussed and the results are compared with other organometallic crystals. The nonlinear refractive index, absorption coefficient and third order susceptibility are estimated to be −1.88 × 10 −11 cm 2/W, 8.65 × 10 −6 cm/W and 6.58 × 10 −9 esu, respectively. The optical absorption of MMTC single crystal was recorded and the corresponding direct band gap is found to be 4.2 eV. The phase matching and laser induced damage threshold studies are also carried out. The FT-IR and photoluminescence spectroscopic techniques were employed to identify the composition and luminescence nature of the crystal.

Synthesis, growth, and characterization of nonlinear optical material l-arginine iodate crystal

Single crystals of nonlinear optical l-arginine iodate ( l-Arg·2HIO 3) (C 6H 14N 4O 2·2HIO 3), were successfully grown for the first time by the temperature-lowering method and also by the slow evaporation method at a constant temperature (30 °C) from its aqueous solution at pH value of 6. Crystals were of average dimensions 3 × 2.5 × 1.0 cm 3 by optimizing the growth parameters. Initially, solubility studies were carried out for four different solvents such as water, water–methanol, water–ethanol, and water–acetone. Among the four solvents, the solubility of l-Arg·2HIO 3 was found to be the highest in water and hence crystallization of l-Arg·2HIO 3 was carried out from aqueous solution. Morphology studies reveal that the crystals grow with reasonable growth rate along the [100], [001], [110¯] and [011] direction. As-grown crystals were characterized by density measurement, X-ray powder diffraction studies, infrared spectrophotometer, UV–Vis spectrometer, laser induced damage threshold studies and nonlinear optical study.