Flux Growth and Properties of Volatile Bromine-Containing UV Nonlinear Optical Crystal K3B6O10Br

A UV Nonlinear optical (NLO) crystal is one of the key devices in all-solid-state laser technology, and borate halides show outstanding potential due to their abundant structural diversity and short UV cut-off edges. In this article, the sizable UV NLO crystal of K3B6O10Br (KBOB) has been grown with lead-containing and lead-free fluxes systems using the high-temperature top-seeded solution growth (TSSG) method. Energy Dispersive X-ray Spectroscopy (EDS) and transmittance spectra illustrate the influence of Pb2+ ions on the transmittance properties and laser-induced damage threshold (LDT). The thermal property, namely, thermal expansion, thermal conductivity, and thermal diffusivity curves, were characterized. Moreover, a small variation of thermal refractive indexes was analyzed to illustrate the advantage of KBOB in the application for temperature-fluctuated specific regions.

YMgB5O10 crystal preparation and attractive multi-wavelength emission characteristics of doping Nd3+ ions

The pure and Nd3+-doped YMgB5O10 (YMB, Nd:YMB) crystals were grown successfully by the top-seeded solution growth method with composite fluxes Li2O-B2O3-LiF. The systematic investigation of crystal structure, transmission spectrum, band...

Optimization of fluxes for Yb3+:YMgB5O10 crystal growth and intense multi-wavelength emission characteristics in spectra and laser performances

Yb3+-doped YMgB5O10 (Yb:YMB) crystals with better crystalline quality were grown successfully using the optimized flux of Li2O-B2O3-LiF instead of traditional K2O3-MoO3 flux by the top-seeded solution growth method. The systematic...

Crystal Growth and Properties Characteriazation of Nd3+:Na5Lu(MoO4)4 for Continuous Multi-Wavelength NIR Laser Emission

A new Nd3+ ions doped NIR laser crystal of Na5Lu(MoO4)4 was grown in a 4Na2O–5MoO3 flux through the top-seeded solution growth (TSSG) technique. Thermal analysis indicated that Na5Lu(MoO4)4 melted incongruently...

Electro-Optic Intensity Modulation in Fe-Doped KTa0.65Nb0.35O3 Crystals

KTa0.65Nb0.35O3 and Fe-doped KTa0.65Nb0.35O3 crystals were grown by the top-seeded solution growth method (TSSG). Fe ion doping significantly improves the electro-optic properties of cubic KTN crystals. We describe their electro-optic modulation theory and experimental research. The electro-optic modulation waveform deduced by theoretical calculation is basically consistent with the waveform measured in the experiment. We observed the attenuation of light modulation under multiple voltage cycles. The modulation curve of the crystal is inconsistent when the crystal voltage is boosting and bucking. Under the same voltage condition, the higher the incident light power, the faster the modulation depth attenuation. In this experiment, the size of the KTN crystal chip is 6 mm × 5 mm × 2 mm. We obtain the effective electro-optic coefficient as s11 − s12 = 1.34 × 10−15 m2/V2; the half-wave voltage near the Curie temperature is 39 V.

Optimal Control of SiC Crystal Growth in the RF-TSSG System Using Reinforcement Learning

We have developed a reinforcement learning (RL) model to control the melt flow in the radio frequency (RF) top-seeded solution growth (TSSG) process for growing more uniform SiC crystals with a higher growth rate. In the study, the electromagnetic field (EM) strength is controlled by the RL model to weaken the influence of Marangoni convection. The RL model is trained through a two-dimensional (2D) numerical simulation of the TSSG process. As a result, the growth rate under the control of the RL model is improved significantly. The optimized RF-coil parameters based on the control strategy for the 2D melt flow are used in a three-dimensional (3D) numerical simulation for model validation, which predicts a higher and more uniform growth rate. It is shown that the present RL model can significantly reduce the development cost and offers a useful means of finding the optimal RF-coil parameters.