Using femtosecond visible light and terahertz pulses as external perturbations, the researchers studied the second harmonic generation (SHG) effect of photoexcited yttrium oxide (BiCoO3).
Nonlinear
wholesale large size infrared Silicon optics can change laser color from femtosecond time scale
This study highlights the importance of Co3 ion orbital excitation; this study was driven by terahertz radiation pulses, providing clues to improve the performance of nonlinear crystal nonlinear optical phenomena on a femtosecond time scale.
The use of SHG to double the frequency of the laser (and thus its color) requires reversing the polar crystal whose symmetry is destroyed. In view of this, the identification of a SHG crystal that can induce strong is an important research topic, so this property can be used in the field of materials science.
Observing a nonlinear optical phenomenon such as SHG requires a finite second-order polarization rate, which occurs in any polar structure, strong laser or pulse inside without reverse symmetry. In the perovskite-type cobalt oxide BiCoO3 used in this study, the oxygen displacement and Co-O5 cone along the c-axis were exhibited in the test unit, resulting in symmetric fracture and great spontaneous polarization at room temperature.
For laser pulses, a strong electromagnetic pulse with an electric field of up to about 1 MV/cm in the terahertz energy region developed by Hideki Hirori and his team from iCems can be used to achieve ultra-fast control of the nonlinear behavior of BiCoO 3 . .
His colleagues specifically understood the change in the intensity of the
wholesale large size optical grade sapphire optics when irradiated with terahertz laser pulses at room temperature. It is worth noting that SHG achieves an unprecedented enhancement of more than 50%, indicating that the use of terahertz lasers in this way can significantly improve the quality factor of
wholesale LiSAF, LiSGaF and LiCAF laser crystals. In addition, this effect occurs on the 100fs time scale, indicating that this property can be applied to ultrafast optoelectronic devices.
Future studies of the photoexcited states of BiCoO3 and other polar oxide materials will consider higher order nonlinear optical responses and ultrafast structural measurements using terahertz pulses to shed light on the more technical details of these fascinating materials.
