Related papers: Materials processing with tightly focused femtosec…

This letter is the first demonstration of material modification using tightly focused femtosecond laser vortex beams. Double-charge femtosecond vortices were synthesized with the polarization-singularity beam converter described in Ref [1]…

We describe an optical beam converter for an efficient transformation of Gaussian femtosecond laser beams to single- or double-charge vortex beams showing no spatial or topological charge dispersion. The device achieves a conversion…

Femtosecond laser modification of fused silica enables precise surface tailoring for the fabrication of micro-optical components such as microlenses and diffractive elements. However, the process is governed by laser-matter interactions…

Tightly focused femtosecond laser-beam in the non-ablative regime can induce a shock-wave enough to reach locally pressures in the giga-Pascal range or more. In a single beam configuration, the location of the highest-pressure zone is…

We describe a technique for surface and sub-surface micro-machining of glass substrates using tightly focused femtosecond laser pulses at a wavelength of 1660 nm. Although silicate glass is normally transparent at this wavelength, the…

Fast fabrication of micro-optical elements for generation of optical vortex beams based on the q-plate design is demonstrated by femtosecond (fs) laser ablation of gold film on glass. Q-plates with diameter of ~0.5 mm were made in ~1 min…

The use of femtosecond lasers to introduce controlled stress states has recently been demonstrated in silica glass. We use this technique, in combination with chemical etching, to generate and control stress-induced birefringence over a…

We report the fabrication of large-area phase masks on thin fused-silica substrates that are suitable for shaping multi-terawatt femtosecond laser beams. We apply these phase masks for the generation of intense femtosecond optical vortices.…

Impurity injection into superfluid helium is a simple yet unique method with diverse applications, including high-precision spectroscopy, quantum computing, nano/micro materialsynthesis, and flow visualisation. Quantised vortices are…

Recent results confirm the presence of molecular oxygen proving that recombination of dissociated silica bonds does not occur. This combined with the observation of nanopores within the nanograting structure in silica, leads to a new…

The absorbed laser energy of a femtosecond laser pulse in a transparent material induces a warm dense matter region which relaxation may lead to structural modifications in the surrounding cold matter. The modeling of the…

Non-linear absorption phenomena induced by controlled irradiation with a femtosecond laser beam can be used to tailor materials properties within the bulk of substrates. One of the most successful applications of this technique is the…

We report a novel, polarization dependent, femtosecond laser-induced modification of surface nanostructures of indium, gallium, and arsenic grown on silicon via molecular beam epitaxy, yielding shape control from linear and circular…

Sub-picosecond optical laser processing of metals is actively utilized for modification of a heated surface layer. But for deeper modification of different materials a laser in the hard x-ray range is required. Here, we demonstrate that a…

The formation and the interaction of multiple cavities, induced by tightly focused femtosecond laser pulses, are studied by using a developed numerical tool, including the thermo-elasto-plastic material response. Simulations are performed…

Low-loss single-mode optical waveguide fabrication process in extra-white soda-lime glass is demonstrated. Waveguiding structures are formed in bulk substrates employing femtosecond laser writing technology. The combination of a slit…

We demonstrate numerically and experimentally the generation of powerful supercontinuum vortices from femtosecond vortex beams by using multiple thin fused silica plates. The supercontinuum vortices are shown to preserve the vortex phase…

We report on the generation of optical vortices with few-cycle pulse durations, 500$\mu$J per pulse, at a repetition rate of 1 kHz. To do so, a 25 fs laser beam at 800 nm is shaped with a helical phase and coupled into a hollow core fiber…

Ultrafast pulse optical vortices are spatiotemporal structures with a diverse range of applications. There are different ways to generate them, often restricted to a wavelength range. Likewise, characterization techniques frequently possess…

Femtosecond laser ablation has been demonstrated to be a versatile tool to produce micro/nanoscale features with high precision and accuracy. However, the use of high laser fluence to increase the ablation efficiency usually results in…