A significant level of back reflected laser energy was measured during the interaction of ultra-short, high contrast PW laser pulses with solid targets at 30° incidence. 2D PIC simulations carried out for the experimental conditions show that at the laser-target interface a dynamic regular structure is generated during the interaction, which acts as a grating (quasi-grating) and reflects back a significant amount of incident laser energy. With increasing laser intensity above 10 W/cm the back reflected fraction increases due to the growth of the surface modulation to larger amplitudes. Above 10 W/cm this increase results in the partial destruction of the quasi-grating structure and, hence, in the saturation of the back reflection efficiency. The PIC simulation results are in good agreement with the experimental findings, and, additionally, demonstrate that in presence of a small amount of pre-plasma this regular structure will be smeared out and the back reflection reduced.

Download full-text PDF

Source
http://dx.doi.org/10.1364/OE.24.028104DOI Listing

Publication Analysis

Top Keywords

surface modulation
8
laser energy
8
regular structure
8
laser
5
modulation reflection
4
reflection foil
4
foil targets
4
targets irradiated
4
irradiated petawatt
4
petawatt femtosecond
4

Similar Publications

Heparanase 2 Modulation Inhibits HSV-2 Replication by Regulating Heparan Sulfate.

Viruses

November 2024

Department of Ophthalmology and Visual Sciences, College of Medicine, University of Illinois Chicago, Chicago, IL 60612, USA.

The host enzyme heparanase (HPSE) facilitates the release of herpes simplex virus type 2 (HSV-2) from target cells by cleaving the viral attachment receptor heparan sulfate (HS) from infected cell surfaces. HPSE 2, an isoform of HPSE, binds to but does not possess the enzymatic activity needed to cleave cell surface HS. Our study demonstrates that HSV-2 infection significantly elevates HPSE 2 protein levels, impacting two distinct stages of viral replication.

View Article and Find Full Text PDF

Background/objectives: Considering the large number of candidates in vaccine-testing studies against different pathogens and the amount of time spent in the preclinical and clinical trials, there is a pressing need to develop an improved in vivo system to quickly screen vaccine candidates. The model of a polyester-polyurethane sponge implant provides a rapid analysis of the specific stimulus-response, allowing the study of a compartmentalized microenvironment. The sponge implant's defined measurements were standardized as a compartment to assess the immune response triggered by the vaccinal antigen.

View Article and Find Full Text PDF

A core dielectric cylindrical rod wrapped in a dielectric circular pipe whose outer surface is enclosed by a helical conducting strip grating that is skewed along the axial direction is herein analyzed using the asymptotic strip boundary conditions along with classical vector potential analysis. Targeted for use as a cylindrical holographic antenna, the resultant field solutions facilitate the aperture integration of the equivalent cylindrical surface currents to obtain the radiated far fields. As each rod section of a certain skew angle exhibits a distinct modal attribute; this topology allows for the distribution of the cylindrical surface impedance via the effective refractive index to be modulated, as in gradient-index (GRIN) materials.

View Article and Find Full Text PDF

Selective Detection of Formaldehyde and Nitrogen Dioxide Using Innovative Modeling of SnO Surface Response to Pulsed Temperature Profile.

Sensors (Basel)

December 2024

Laboratoire d'Analyse et d'Architecture des Systèmes (LAAS), Université de Toulouse, CNRS, UPS, 7 Avenue du Colonel Roche, 31031 Toulouse, France.

The need for odor measurement and pollution source identification in various sectors (aeronautic, automobile, healthcare…) has increased in the last decade. Multisensor modules, such as electronic noses, seem to be a promising and inexpensive alternative to traditional sensors that were only sensitive to one gas at a time. However, the selectivity, the non-repetitiveness of their manufacture, and their drift remain major obstacles to the use of electronic noses.

View Article and Find Full Text PDF

The Role of Re-Entrant Microstructures in Modulating Droplet Evaporation Modes.

Micromachines (Basel)

December 2024

Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan Campus, 170 Kessels Road, Brisbane, QLD 4111, Australia.

The evaporation dynamics of sessile droplets on re-entrant microstructures are critical for applications in microfluidics, thermal management, and self-cleaning surfaces. Re-entrant structures, such as mushroom-like shapes with overhanging features, trap air beneath droplets to enhance non-wettability. The present study examines the evaporation of a water droplet on silicon carbide (SiC) and silicon dioxide (SiO) re-entrant structures, focusing on the effects of material composition and solid area fraction on volume reduction, contact angle, and evaporation modes.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!