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 × 10−21 m2 V−2 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 1064 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

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 λ=1.064 μm 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

Second and third order nonlinear optical properties of nanostructured ZnO thin films deposited on α-BBO and LiNbO3

The nanocrystalline ZnO films were deposited on α-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

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 cm⁻² for ZnO microprisms and 560 kW cm⁻² — for ZnO nanowires.Мы сообщаем о наблюдении лазерной генерации при оптической накачке в ZnO микропризмах и нанопроволоках при комнатной температуре. Микропризмы ZnO были выращены на монокристаллических (100) кремниевых подложках с паровой фазы. ZnO нанопроволоки были выращены на стеклянных подложках, покрытых оксидным слоем индия с оловом, путем электрохимического осаждения. Лазерный эффект наблюдался при комнатной температуре в тех случаях, когда мощность оптический накачки превышала 685 кВт см⁻² для ZnO микропризм и 560 кВт см⁻² для ZnO нанопроволок.Ми повідомляємо про спостереження лазерної генерації при оптичному нагнітанні в ZnO мікропризмах і нанодротах за кімнатної температури. Мікропризми ZnO були вирощені з парової фази на монокристалічних (100) кремнієвих підкладках. ZnO нанодроти були вирощені електрохімічним осадженням на скляних підкладках, покритих оксидним шаром індію з оловом. Лазерний ефект спостерігався при кімнатній температурі в тих випадках, коли потужність оптичного нагнітання перевищувала значення 685 кВт см⁻² для ZnO мікропризм і 560 кВт см⁻² для ZnO нанодротів. фази на монокристалічних (100) кремнієвих підкладках. ZnO нанодроти були вирощені електрохімічним осадженням на скляних підкладках, покритих оксидним шаром індію з оловом. Лазерний ефект спостерігався при кімнатній температурі в тих випадках, коли потужність оптичного нагнітання перевищувала значення 685 кВт см⁻² для ZnO мікропризм і 560 кВт см⁻² для ZnO нанодротів

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