相关论文: Materials processing with tightly focused femtosec…
Femtosecond laser ablation is a process that bears both fundamental physics interest and has wide industrial applications. For decades, the lack of probes on the relevant time and length scales has prevented access to the highly…
Twisted tapes are used to induce swirling flow and improve mixing. The flow induced by a 180 degree twisted tape with length (pitch) 60 mm and diameter 25.4 mm in a circular pipe was investigated using Laser Doppler Velocimetry (LDV)…
In this paper we analyze femtosecond laser processing of metals in liquids searching for optimal conditions for predictable ablation. Incident laser pulses are stretched or compressed, self-focused and scattered on bubbles and on surface…
We propose to use femtosecond direct laser writing technique to realize dielectric optical elements from photo-resist materials for the generation of structured light from purely geometrical phase transformations. This is illustrated by the…
Optically levitated and cooled nanoparticles are a new quantum system whose application to the creation of non-classical states of motion and quantum limited sensing is fundamentally limited by recoil and bulk heating. We study the creation…
Structured light and high-intensity ultrafast lasers are two rapidly advancing frontiers in photonics, yet their intersection remains largely unexplored. While ultrafast lasers continue to push the boundaries of peak intensities, structured…
A femtosecond laser is a powerful tool for micromachining of silicon. In this work, large-area laser ablation of crystalline silicon is comprehensively studied using a laser source of pulse width 300 fs at two wavelengths of 343 nm and 1030…
Ultrafast laser ablation is an extremely precise and clean method of removing material, applied in material processing as well as medical applications. And due to its violent nature, it tests our understanding of the interplay between…
Vortices are topological objects carrying quantized orbital angular momentum and have been widely studied in many physical systems for their applicability in information storage and processing. In systems with spin degree of freedom the…
A model for a new electron vortex beam production method is proposed and experimentally demonstrated. The technique calls on the controlled manipulation of the degrees of freedom of the lens aberrations to achieve a helical phase front.…
Ultrashort pulsed laser annealing is an efficient technique for crystallizing amorphous semiconductors with the possibility to obtain polycrystalline films at low temperatures, below the melting point, through non-thermal processes. Here, a…
Laser filamentation in transparent material has a wide range of applications, from three dimensional manufacturing to biological technologies. Various experimental results showed that femtosecond laser pulse filamentation in fused silica…
We report on experimental observations of formation and evolution of transient plasma produced in fused silica glass with spatiotemporally focused (STF) femtosecond laser pulses using a pump-probe shadow imaging technique. Surprisingly, the…
Ultrafast lasers have revolutionized material processing, opening a wealth of new applications in many areas of science. A recent technology that allows the cleaving of transparent materials via non-ablative processes is based on focusing…
Three-dimensional (3D) printing has allowed for production of geometrically complex 3D objects with extreme flexibility, which is currently undergoing rapid expansions in terms of materials, functionalities, as well as areas of application.…
For fused silica irradiated by near-100-fs, 795-nm laser pulses with fluence approaching the damage threshold, the transient transmission spectroscopy based on a wavelength-degenerate pump-probe technique clearly presents two dynamic…
We provide a complete toolkit for coherent control experiments on the nano-scale. By exploiting the second harmonic emission from single (150 nm) nonlinear nano-particles, we show that ultrafast femtosecond laser pulses can be compressed…
We report the first measurement with no approximations of the full field of tightly focused vector beams (NA up to $1.23$) across areas of $\sim 9-49\,\lambda ^2$. Prior to focusing, the structured laser light has a linear or circular…
We introduce a method for shaping a cold atom cloud using a vortex laser beam with a polarization singularity at its center, which creates a point of vanishing intensity. Exploiting this feature we experimentally demonstrate two different…
We present a numerical model which describes the propagation of a single femtosecond laser pulse in a medium of which the optical properties dynamically change within the duration of the pulse. We use a Finite Difference Time Domain (FDTD)…