https://www.selleckchem.com/products/amg-232.html We report on a new technique of silicon surface nanostructuring in liquid with a pair of Gaussian-shaped femtosecond laser pulses. The bubble, generated in liquid near the molten silicon surface by the first pulse, serves as a dynamic microscale obstacle for spatial modulation of the intensity profile of the second pulse following at a certain delay via scattering processes. As a result, the circular ripple patterns with anomalously high surface-relief modulation, undersurface annular nanocavities, and interfacial smoothness are produced at the surface. The possibility of the control over the specific pattern through the laser intensity variation is shown.A common technique to realize the gradient electric field profile that is required in liquid crystal tunable lenses is the use of a weakly conductive layer. Thanks to this layer, an applied voltage with a certain frequency allows us to obtain a refractive index profile that is required for the lens operation. Due to the limited degrees of freedom, however, it is not possible to avoid aberrations in a weakly conductive layer-based tunable lens for a continuously tunable focal length. In this work, we discuss the use of additional higher frequency components in the voltage signal to reduce the lens aberrations drastically.Mid-infrared femtosecond vortex beams generated by optical parametric oscillators (OPO) are reported for the first time, to the best of our knowledge. Order-tunable femtosecond Hermite-Gauss beams from the first to sixth order are produced from a synchronously pumped OPO and then converted into the corresponding first through sixth-order femtosecond vortex beams by a cylindrical lens mode converter. By slightly tuning the cavity length, the wavelength of the vortex beam can be continuously tunable in the range from 2323 to 2382 nm, and the pulse duration can be changeable from $\sim400\;\rm fs$∼400fs to $\sim1.1\;\rm ps$∼1.1ps. The work provides a fl