UV-illuminated, paraelectric-phased potassium tantalate niobate (KTN) single crystals mitigate the beam deformation effects of femtosecond pulsed lasers in KTN deflectors. UV light illumination can control the amount of trapped charge present and minimize domain inversion in KTN deflectors, owing to its generated electron-hole pairs. This enables high beam quality deflection of fs pulsed lasers, with access to larger deflection angles, deflection speeds, and modulation switching ratios.
View Article and Find Full Text PDFWe report a new, to the best of our knowledge, type of SI-GaAs photoconductive semiconductor switch (PCSS) with nanostructures. Since light can enter from both the top and side surfaces of nanostructures, the effective penetration depth is significantly increased. Lower on-state resistance and a longer lock-on time have been achieved in the nonlinear mode with this design, as well as a lower triggering fluence in the linear mode.
View Article and Find Full Text PDFSpatially 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.
View Article and Find Full Text PDFIn 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.
View Article and Find Full Text PDFThis publisher's note contains corrections to Opt. Lett.44, 5557 (2019)OPLEDP0146-959210.
View Article and Find Full Text PDFMost 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.
View Article and Find Full Text PDFWe 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.
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