Avoiding water reservoir effects in ALD of functional complex alkali oxides by using O as the oxygen source.

Toxic Pb-containing piezo-, pyro- and ferroelectrics continue to dominate the market even though they were banned from use in consumer products more than a decade ago. There is a strong need for sustainable alternatives, but the lack of facile synthesis routes for thin films exhibiting suitable functional properties have limited the transition from Pb workhorse materials like Pb(Zr,Ti)O and Pb(Mg,Nb)O - PbTiO. Atomic layer deposition has proven capable of the deposition of possible successors, such as LiNbO, (K,Na)NbO and K(Ta,Nb)O, albeit with limited control due to water reservoir effects resulting from the hygroscopicity of intermediate products.

Analysis on the electric field distribution in a relaxor ferroelectric KTN crystal near field-induced phase transition using optical deflection measurements.

Spatially analyzing non-uniform distributions of electric phenomena such as electric field and permittivity in ferroelectric devices is very challenging. In this study, we apply an optical beam deflection method to map the non-uniform electric phenomena in relaxor ferroelectric potassium tantalate niobate (KTN) crystals. To adequately correlate the physical parameters and their spatial distributions in KTN crystals, a general model that describes the giant electro-optic response and associated beam deflection is derived.

Anomalous bi-directional scanning electro-optic KTN devices with UV-assisted electron and hole injections.

In this Letter, we reported anomalous electro-optic potassium tantalate niobate (KTN) devices, in which both electrons and holes were injected into the KTN crystal via ultraviolet (UV) illumination-assisted charge injection. This could not only significantly enhance the performance of electro-optic devices (e.g.

Enhanced electro-optic beam deflection of relaxor ferroelectric KTN crystals by electric-field-induced high permittivity: publisher's note.

This publisher's note contains corrections to Opt. Lett.44, 5557 (2019)OPLEDP0146-959210.

Enhanced electro-optic beam deflection of relaxor ferroelectric KTN crystals by electric-field-induced high permittivity.

Most applications of a ferroelectric-based electro-optic (EO) beam deflector have been limited by the high applied voltage. In this Letter, we report a dramatically increased EO beam deflection in relaxor ferroelectric potassium tantalate niobate (KTN) crystals by using the electric-field-enhanced permittivity. Due to the existence of the electric-field-induced phase transition in relaxor ferroelectric materials, the dielectric permittivity can be substantially increased by the applied electric field at a certain temperature.

Ruby fluorescence-enabled ultralong lock-on time high-gain gallium arsenic photoconductive semiconductor switch.

We report a new type of photoconductive semiconductor switch (PCSS), consisting of a semi-insulating gallium arsenic (GaAs) substrate and a front-bonded ruby crystal. The 532 nm laser pulses from an Nd-YAG laser incident on the front surface of the ruby crystal. A portion of the laser pulse passes through the crystal and reaches the GaAs substrate, and the remaining portion of the laser pulse is absorbed by the ruby crystal.

High speed non-mechanical two-dimensional KTN beam deflector enabled by space charge and temperature gradient deflection.

In this paper, a high-speed non-mechanical two-dimensional KTN beam deflector is reported. The scanning mechanism is based on the combination of space charge controlled beam deflection and temperature gradient enabled beam deflection in a nanodisordered KTN crystal. Both theoretical analyses and experimental investigations are provided, which agree relatively well with each other.

Fluence-induced reversal of saturable absorption in a ruthenium-based porphyrin.

Experimental nonlinear absorption data obtained using the open-aperture Z-scan technique are presented for 2, 3, 7, 8, 12, 17, 18-octaethyl-21H, 23H-porphine ruthenium (II) carbonyl in tetrahydrofuran. These data show saturation of nonlinear absorption dominating at low fluence but being overcome by induced absorption (reverse saturable absorption) at high fluence. Large-angle scattering measurements demonstrate that the induced absorption is real and not merely the result of scattering of light outside of the collection aperture of the detector by scattering centers induced at high fluence.

Three order increase in scanning speed of space charge-controlled KTN deflector by eliminating electric field induced phase transition in nanodisordered KTN.

In this paper, we report a three orders-of-magnitude increase in the speed of a space-charge-controlled KTN beam deflector achieved by eliminating the electric field-induced phase transition (EFIPT) in a nanodisordered KTN crystal. Previously, to maximize the electro-optic effect, a KTN beam deflector was operated at a temperature slightly above the Curie temperature. The electric field could cause the KTN to undergo a phase transition from the paraelectric phase to the ferroelectric phase at this temperature, which causes the deflector to operate in the linear electro-optic regime.

Giant electro-optic effect in nanodisordered KTN crystals.

The electro-optic (EO) effect in nanodisordered potassium tantalate niobate (KTN) crystal is quantitatively investigated. It is found out that the EO coefficient of nanodisordered KTN crystal depends not only on the cooling temperature but also on the cooling rate. A larger EO coefficient can be obtained by employing a faster cooling rate.

Kovacs effect enhanced broadband large field of view electro-optic modulators in nanodisordered KTN crystals.

The unique physical effect-Kovacs effect is explored to enhance the performance of EO modulators by employing the non-thermal equilibrium state nanodisordered KTN crystals created by super-cooling process, which can have a significant 3.5 fold increase in quadratic electro-optic coefficient. This enables to reduce the switching half wave voltage (almost by half) so that a broadband (~GHz range) and large field of view (+/-30 deg) electro-optic modulator can be realized with much lowered driving power, which can be very useful for a variety of applications: laser Q-switches, laser pulse shaping, high speed optical shutters and modulating retro reflectors.