29 research outputs found
Third harmonic generation in LiKB4O7 single crystal
The third order nonlinear optical properties of the lithium potassium borate (LiKB4O7) single crystal have been investigated by means of the rotational Maker fringe technique using Nd:YAG laser at 1064 nm working in picosecond regime. The value of the third order nonlinear optical susceptibility was calculated using the theoretical model of Kajzar et al. and was found to be about 1.4 Γ 10β21 m2 Vβ2 that is one order higher than that of fused silica
Influence of Ag, Cu dopants on the second and third harmonic response of ZnO films
Silver- and copper-doped ZnO films were prepared by radio-frequency (RF)-magnetron sputtering on glass and quartz substrates. The influence of dopants content on the microstructural evolution and optical as well as nonlinear optical (NLO) properties were investigated. It has been found that the grain sizes were enlarged with increasing of Ag, Cu dopants amount in ZnO films. The Ag or Cu doping leads to the optical band gap narrowing. Besides, the second-order NLO response of Ag- and Cu-doped ZnO films is lower than that of undoped ZnO film. The second harmonic generation (SHG) efficiency of the ZnO:Ag film was found to be higher than that of the ZnO:Cu film at the similar concentration of dopant. In addition, the decrease of the third harmonic generation (THG) response is observed in ZnO films with increasing of Ag or Cu dopant amount
Quadratic nonlinear optical parameters of 7% MgO-doped LiNbO3 crystal
Pure and 7% MgO-doped lithium niobate (LiNbO3) single crystals were grown by the Czochralski technique. The shift of optical absorption edge in 7% MgO-doped crystal in direction of shorter wavelength compared to undoped crystal was observed. The second harmonic generation measurements of 7% MgO-doped LiNbO3 crystal were performed at room temperature by means of the rotational Maker fringe technique using Nd:YAG laser generating at 1064Β nm in picoseconds regime. Experimentally obtained value of nonlinear optical coefficient d33 for 7% MgO-doped LiNbO3 was found to be less than for undoped crystal but higher than for 5% MgO-doped. I-type phase-matched second harmonic generation was achieved and the value of phase-matched angle was calculated. High quadratic nonlinearity together with tolerance to intensive laser irradiation makes 7% MgO-doped LiNbO3 crystal interesting for application in optoelectronics
Second and third order nonlinear optical properties of nanostructured ZnO thin films deposited on Ξ±-BBO and LiNbO3
The nanocrystalline ZnO films were deposited on Ξ±-BaB2O4 (0 0 1 2) and LiNbO3 (0 0 0 1) single crystals by RF-magnetron sputtering technique. Their structure was studied using X-ray diffractometry, scanning electron microscopy and atomic force microscopy. Besides, the optical absorption spectra were investigated. The second and third harmonic generation measurements were performed by means of the rotational Maker fringe technique using Nd:YAG laser at 1064 nm in picoseconds regime. Finally, the second and third order nonlinear susceptibilities were determined and their values have been found and compared
Linear and nonlinear optical properties of ZnO/PMMA nanocomposite films
The nanoscale crystals (NCs) of ZnO were embedded into polymethylmethacrylate (PMMA) polymeric matrix and nanocomposite films were prepared by modified spin coating method. The surface of the ZnO/PMMA nanocomposite films has been investigated using atomic force and scanning electron microscopy. The prepared films are highly transparent, the ultraviolet-visible spectra show their high optical quality. The second and third harmonic generation (SHG and THG) studies of ZnO/PMMA nanocomposite films with different concentrations of ZnO NCs were carried out at Ξ»=1.064 ΞΌm and the effective values of the second and third order nonlinear susceptibilities were estimated to be higher than that of ZnO bulk for the films at low concentration of ZnO NCs. This could indicate that surface effects in ZnO/PMMA nanocomposite films have a dominant role over bulk effects for the SHG and THG processes
Optical properties of ZnO/PMMA nanocomposite films
The ZnO nanocrystals (ZnO NCs) with particle size, less than 100 nm, have been blended with polymethylmethacrylate (PMMA) by solution mixing to prepare PMMA/ZnO nanocomposite films. The structure of ZnO/PMMA nanocomposite films was characterized using X-ray diffractometry. The prepared nanocomposite films are highly transparent and a clear excitonic peak is observed in their absorption spectra. Measurements of temperature evolution of the photoluminescence (PL) spectra show intensive UV emission peak corresponding to the donor-bound excitons with binding energy of 51 meV and green emission band related to the intrinsic defects in ZnO. The temperature evolution of the emission peaks energy position, intensity and integral intensity in ZnO/PMMA nanocomposite films were examined
Room-temperature ultraviolet laser emission from ZnO hexagonal microprisms and nanowires
We report the observation of optically pumped laser generation in ZnO microprisms and nanowires at room temperature. The ZnO microprisms were grown on the single crystal (100) silicon substrates by a solid-vapor-phase process. The ZnO nanowires were grown on a glass substrate coated with indium tin oxide by the electrochemical deposition. Laser effect was observed at room temperature at the optically pump power higher than 685 kW cmβ»Β² for ZnO microprisms and 560 kW cmβ»Β² β for ZnO nanowires.ΠΡ ΡΠΎΠΎΠ±ΡΠ°Π΅ΠΌ ΠΎ Π½Π°Π±Π»ΡΠ΄Π΅Π½ΠΈΠΈ Π»Π°Π·Π΅ΡΠ½ΠΎΠΉ Π³Π΅Π½Π΅ΡΠ°ΡΠΈΠΈ ΠΏΡΠΈ ΠΎΠΏΡΠΈΡΠ΅ΡΠΊΠΎΠΉ Π½Π°ΠΊΠ°ΡΠΊΠ΅ Π² ZnO ΠΌΠΈΠΊΡΠΎΠΏΡΠΈΠ·ΠΌΠ°Ρ
ΠΈ Π½Π°Π½ΠΎΠΏΡΠΎΠ²ΠΎΠ»ΠΎΠΊΠ°Ρ
ΠΏΡΠΈ ΠΊΠΎΠΌΠ½Π°ΡΠ½ΠΎΠΉ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΠ΅. ΠΠΈΠΊΡΠΎΠΏΡΠΈΠ·ΠΌΡ ZnO Π±ΡΠ»ΠΈ Π²ΡΡΠ°ΡΠ΅Π½Ρ Π½Π° ΠΌΠΎΠ½ΠΎΠΊΡΠΈΡΡΠ°Π»Π»ΠΈΡΠ΅ΡΠΊΠΈΡ
(100) ΠΊΡΠ΅ΠΌΠ½ΠΈΠ΅Π²ΡΡ
ΠΏΠΎΠ΄Π»ΠΎΠΆΠΊΠ°Ρ
Ρ ΠΏΠ°ΡΠΎΠ²ΠΎΠΉ ΡΠ°Π·Ρ. ZnO Π½Π°Π½ΠΎΠΏΡΠΎΠ²ΠΎΠ»ΠΎΠΊΠΈ Π±ΡΠ»ΠΈ Π²ΡΡΠ°ΡΠ΅Π½Ρ Π½Π° ΡΡΠ΅ΠΊΠ»ΡΠ½Π½ΡΡ
ΠΏΠΎΠ΄Π»ΠΎΠΆΠΊΠ°Ρ
, ΠΏΠΎΠΊΡΡΡΡΡ
ΠΎΠΊΡΠΈΠ΄Π½ΡΠΌ ΡΠ»ΠΎΠ΅ΠΌ ΠΈΠ½Π΄ΠΈΡ Ρ ΠΎΠ»ΠΎΠ²ΠΎΠΌ, ΠΏΡΡΠ΅ΠΌ ΡΠ»Π΅ΠΊΡΡΠΎΡ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΠΎΡΠ°ΠΆΠ΄Π΅Π½ΠΈΡ. ΠΠ°Π·Π΅ΡΠ½ΡΠΉ ΡΡΡΠ΅ΠΊΡ Π½Π°Π±Π»ΡΠ΄Π°Π»ΡΡ ΠΏΡΠΈ ΠΊΠΎΠΌΠ½Π°ΡΠ½ΠΎΠΉ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΠ΅ Π² ΡΠ΅Ρ
ΡΠ»ΡΡΠ°ΡΡ
, ΠΊΠΎΠ³Π΄Π° ΠΌΠΎΡΠ½ΠΎΡΡΡ ΠΎΠΏΡΠΈΡΠ΅ΡΠΊΠΈΠΉ Π½Π°ΠΊΠ°ΡΠΊΠΈ ΠΏΡΠ΅Π²ΡΡΠ°Π»Π° 685 ΠΊΠΡ ΡΠΌβ»Β² Π΄Π»Ρ ZnO ΠΌΠΈΠΊΡΠΎΠΏΡΠΈΠ·ΠΌ ΠΈ 560 ΠΊΠΡ ΡΠΌβ»Β² Π΄Π»Ρ ZnO Π½Π°Π½ΠΎΠΏΡΠΎΠ²ΠΎΠ»ΠΎΠΊ.ΠΠΈ ΠΏΠΎΠ²ΡΠ΄ΠΎΠΌΠ»ΡΡΠΌΠΎ ΠΏΡΠΎ ΡΠΏΠΎΡΡΠ΅ΡΠ΅ΠΆΠ΅Π½Π½Ρ Π»Π°Π·Π΅ΡΠ½ΠΎΡ Π³Π΅Π½Π΅ΡΠ°ΡΡΡ ΠΏΡΠΈ ΠΎΠΏΡΠΈΡΠ½ΠΎΠΌΡ Π½Π°Π³Π½ΡΡΠ°Π½Π½Ρ Π² ZnO ΠΌΡΠΊΡΠΎΠΏΡΠΈΠ·ΠΌΠ°Ρ
Ρ Π½Π°Π½ΠΎΠ΄ΡΠΎΡΠ°Ρ
Π·Π° ΠΊΡΠΌΠ½Π°ΡΠ½ΠΎΡ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΠΈ. ΠΡΠΊΡΠΎΠΏΡΠΈΠ·ΠΌΠΈ ZnO Π±ΡΠ»ΠΈ Π²ΠΈΡΠΎΡΠ΅Π½Ρ Π· ΠΏΠ°ΡΠΎΠ²ΠΎΡ ΡΠ°Π·ΠΈ Π½Π° ΠΌΠΎΠ½ΠΎΠΊΡΠΈΡΡΠ°Π»ΡΡΠ½ΠΈΡ
(100) ΠΊΡΠ΅ΠΌΠ½ΡΡΠ²ΠΈΡ
ΠΏΡΠ΄ΠΊΠ»Π°Π΄ΠΊΠ°Ρ
. ZnO Π½Π°Π½ΠΎΠ΄ΡΠΎΡΠΈ Π±ΡΠ»ΠΈ Π²ΠΈΡΠΎΡΠ΅Π½Ρ Π΅Π»Π΅ΠΊΡΡΠΎΡ
ΡΠΌΡΡΠ½ΠΈΠΌ ΠΎΡΠ°Π΄ΠΆΠ΅Π½Π½ΡΠΌ Π½Π° ΡΠΊΠ»ΡΠ½ΠΈΡ
ΠΏΡΠ΄ΠΊΠ»Π°Π΄ΠΊΠ°Ρ
, ΠΏΠΎΠΊΡΠΈΡΠΈΡ
ΠΎΠΊΡΠΈΠ΄Π½ΠΈΠΌ ΡΠ°ΡΠΎΠΌ ΡΠ½Π΄ΡΡ Π· ΠΎΠ»ΠΎΠ²ΠΎΠΌ. ΠΠ°Π·Π΅ΡΠ½ΠΈΠΉ Π΅ΡΠ΅ΠΊΡ ΡΠΏΠΎΡΡΠ΅ΡΡΠ³Π°Π²ΡΡ ΠΏΡΠΈ ΠΊΡΠΌΠ½Π°ΡΠ½ΡΠΉ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΡ Π² ΡΠΈΡ
Π²ΠΈΠΏΠ°Π΄ΠΊΠ°Ρ
, ΠΊΠΎΠ»ΠΈ ΠΏΠΎΡΡΠΆΠ½ΡΡΡΡ ΠΎΠΏΡΠΈΡΠ½ΠΎΠ³ΠΎ Π½Π°Π³Π½ΡΡΠ°Π½Π½Ρ ΠΏΠ΅ΡΠ΅Π²ΠΈΡΡΠ²Π°Π»Π° Π·Π½Π°ΡΠ΅Π½Π½Ρ 685 ΠΊΠΡ ΡΠΌβ»Β² Π΄Π»Ρ ZnO ΠΌΡΠΊΡΠΎΠΏΡΠΈΠ·ΠΌ Ρ 560 ΠΊΠΡ ΡΠΌβ»Β² Π΄Π»Ρ ZnO Π½Π°Π½ΠΎΠ΄ΡΠΎΡΡΠ². ΡΠ°Π·ΠΈ Π½Π° ΠΌΠΎΠ½ΠΎΠΊΡΠΈΡΡΠ°Π»ΡΡΠ½ΠΈΡ
(100) ΠΊΡΠ΅ΠΌΠ½ΡΡΠ²ΠΈΡ
ΠΏΡΠ΄ΠΊΠ»Π°Π΄ΠΊΠ°Ρ
. ZnO Π½Π°Π½ΠΎΠ΄ΡΠΎΡΠΈ Π±ΡΠ»ΠΈ Π²ΠΈΡΠΎΡΠ΅Π½Ρ Π΅Π»Π΅ΠΊΡΡΠΎΡ
ΡΠΌΡΡΠ½ΠΈΠΌ ΠΎΡΠ°Π΄ΠΆΠ΅Π½Π½ΡΠΌ Π½Π° ΡΠΊΠ»ΡΠ½ΠΈΡ
ΠΏΡΠ΄ΠΊΠ»Π°Π΄ΠΊΠ°Ρ
, ΠΏΠΎΠΊΡΠΈΡΠΈΡ
ΠΎΠΊΡΠΈΠ΄Π½ΠΈΠΌ ΡΠ°ΡΠΎΠΌ ΡΠ½Π΄ΡΡ Π· ΠΎΠ»ΠΎΠ²ΠΎΠΌ. ΠΠ°Π·Π΅ΡΠ½ΠΈΠΉ Π΅ΡΠ΅ΠΊΡ ΡΠΏΠΎΡΡΠ΅ΡΡΠ³Π°Π²ΡΡ ΠΏΡΠΈ ΠΊΡΠΌΠ½Π°ΡΠ½ΡΠΉ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΡ Π² ΡΠΈΡ
Π²ΠΈΠΏΠ°Π΄ΠΊΠ°Ρ
, ΠΊΠΎΠ»ΠΈ ΠΏΠΎΡΡΠΆΠ½ΡΡΡΡ ΠΎΠΏΡΠΈΡΠ½ΠΎΠ³ΠΎ Π½Π°Π³Π½ΡΡΠ°Π½Π½Ρ ΠΏΠ΅ΡΠ΅Π²ΠΈΡΡΠ²Π°Π»Π° Π·Π½Π°ΡΠ΅Π½Π½Ρ 685 ΠΊΠΡ ΡΠΌβ»Β² Π΄Π»Ρ ZnO ΠΌΡΠΊΡΠΎΠΏΡΠΈΠ·ΠΌ Ρ 560 ΠΊΠΡ ΡΠΌβ»Β² Π΄Π»Ρ ZnO Π½Π°Π½ΠΎΠ΄ΡΠΎΡΡΠ²
Tuning a sign of magnetoelectric coupling in paramagnetic NH2(CH3)2Al1-xCrx(SO4)*6H2O crystals by metal ion substitution
Hybrid organometallic systems offer a wide range of functionalities,
including magnetoelectric interactions. However, the ability to design
on-demand ME coupling remains challenging despite a variety of host-guest
configurations and ME phases coexistence possibilities. Here, we report the
effect of metal-ion substitution on the magnetic and electric properties in the
paramagnetic ferroelectric DMAAS crystals. Doing so we are able to induce and
even tune a sign of the ME interactions in the paramagnetic ferroelectric
state. Both studied samples with 6.5% and 20% of Cr become paramagnetic,
contrary to the initial diamagnetic compound. Due to the isomorphous
substitution with Cr the ferroelectric phase transition temperature increases
nonlinearly, with the shift being larger for the sample with Cr content of
6.5%. A magnetic field applied along the polar c axis increases
ferroelectricity for this sample and shifts Tc to higher values, while inverse
effects are observed for sample containing 20% of Cr. The ME coupling
coefficient of 1.7ns/m found for a crystal with 20% of Cr is among the highest
reported up to now. The observed sign change of ME coupling coefficient with a
small change in Cr content paves the way for ME coupling engineering.Comment: 7 pages, 6 figures. New Organometallic Magnetoelectric and
Ferroelectric compoun