Fourier Spectrometer based on Wide-range and Phase-locked Michelson Interferometer with Femtosecond Laser Excitation

2010 ◽  
Vol 23 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Zi-xin Wang ◽  
Xiang-sheng Xie ◽  
Jun-qi Deng ◽  
Jian-ying Zhou
Keyword(s):  
Femtosecond Laser ◽  
Laser Excitation ◽  
Michelson Interferometer ◽  
Fourier Spectrometer ◽  
Wide Range

scholarly journals Direct light–induced spin transfer between different elements in a spintronic Heusler material via femtosecond laser excitation

2020 ◽  
Vol 6 (3) ◽  
pp. eaaz1100 ◽  
Author(s):  
Phoebe Tengdin ◽  
Christian Gentry ◽  
Adam Blonsky ◽  
Dmitriy Zusin ◽  
Michael Gerrity ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Time Scales ◽  
Density Functional ◽  
Laser Excitation ◽  
High Harmonic ◽  
Density Functional Theory Calculations ◽  
Spin Transfer ◽  
Magnetic Interactions ◽  
Magnetic Sublattice ◽  
Wide Range

Heusler compounds are exciting materials for future spintronics applications because they display a wide range of tunable electronic and magnetic interactions. Here, we use a femtosecond laser to directly transfer spin polarization from one element to another in a half-metallic Heusler material, Co2MnGe. This spin transfer initiates as soon as light is incident on the material, demonstrating spatial transfer of angular momentum between neighboring atomic sites on time scales < 10 fs. Using ultrafast high harmonic pulses to simultaneously and independently probe the magnetic state of two elements during laser excitation, we find that the magnetization of Co is enhanced, while that of Mn rapidly quenches. Density functional theory calculations show that the optical excitation directly transfers spin from one magnetic sublattice to another through preferred spin-polarized excitation pathways. This direct manipulation of spins via light provides a path toward spintronic devices that can operate on few-femtosecond or faster time scales.

Femtosecond laser structuring of permeable and resorbable biomaterial

2021 ◽  
Vol 7 (2) ◽  
pp. 713-716
Author(s):  
Swen Grossmann ◽  
Sabine Illner ◽  
Robert Ott ◽  
Grit Rhinow ◽  
Carsten Tautorat ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Biomedical Applications ◽  
Mechanical Characteristics ◽  
Membrane Properties ◽  
Fiber Network ◽  
Laser Technology ◽  
Laser Structuring ◽  
Wide Range ◽  
Nanofiber Membranes ◽  
Post Production

Abstract Bioresorbable nanofiber nonwovens with their fascinating properties provide a wide range of potential biomedical applications. Modification of the material enables the adjustment of mechanical and biological characteristics depending on the desired application. Due to the nanosized fiber network, post-production structuring is very challenging. Within this study, we use femtosecond laser technology for structuring permeable and resorbable electrospun poly-L-lactide (PLLA) membranes. We show that this post-production process can be used without disturbing the fiber network near the structured areas. Furthermore, the modification of the water permeability and mechanical characteristics due to the laser structuring was investigated. The results prove femtosecond laser technology to be a promising method for the adjustment of the membrane properties and which in consequence can help to optimize cell adhesion, enable revascularization and open up applications of nanofiber membranes in personalized medicine.

scholarly journals Fluence-dependent dynamics of the 5d6s exchange splitting in Gd metal after femtosecond laser excitation

2016 ◽  
Vol 55 (7S3) ◽  
pp. 07MD02 ◽  
Author(s):  
Björn Frietsch ◽  
Robert Carley ◽  
Markus Gleich ◽  
Martin Teichmann ◽  
John Bowlan ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Excitation ◽  
Exchange Splitting

scholarly journals Electrical Impedance of Surface Modified Porous Titanium Implants with Femtosecond Laser

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 461
Author(s):  
Paula Navarro ◽  
Alberto Olmo ◽  
Mercè Giner ◽  
Marleny Rodríguez-Albelo ◽  
Ángel Rodríguez ◽  
...  
Keyword(s):  
Cell Culture ◽  
Femtosecond Laser ◽  
Laser Treatment ◽  
Electrical Impedance ◽  
Porous Titanium ◽  
Titanium Implants ◽  
Electrical Impedance Spectroscopy ◽  
Wide Range ◽  
Titanium Surfaces ◽  
Surface Modified

The chemical composition and surface topography of titanium implants are essential to improve implant osseointegration. The present work studies a non-invasive alternative of electrical impedance spectroscopy for the characterization of the macroporosity inherent to the manufacturing process and the effect of the surface treatment with femtosecond laser of titanium discs. Osteoblasts cell culture growths on the titanium surfaces of the laser-treated discs were also studied with this method. The measurements obtained showed that the femtosecond laser treatment of the samples and cell culture produced a significant increase (around 50%) in the absolute value of the electrical impedance module, which could be characterized in a wide range of frequencies (being more relevant at 500 MHz). Results have revealed the potential of this measurement technique, in terms of advantages, in comparison to tiresome and expensive techniques, allowing semi-quantitatively relating impedance measurements to porosity content, as well as detecting the effect of surface modification, generated by laser treatment and cell culture.

scholarly journals Effect of Laser Pulse Overlap and Scanning Line Overlap on Femtosecond Laser-Structured Ti6Al4V Surfaces

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 969 ◽  
Author(s):  
Georg Schnell ◽  
Ulrike Duenow ◽  
Hermann Seitz
Keyword(s):  
Laser Pulse ◽  
Femtosecond Laser ◽  
Surface Topography ◽  
Cell Attachment ◽  
Surface Structures ◽  
Laser Source ◽  
Laser Machining ◽  
Scanning Strategy ◽  
Wide Range ◽  
Scanning Line

Surface structuring is a key factor for the tailoring of proper cell attachment and the improvement of the bone-implant interface anchorage. Femtosecond laser machining is especially suited to the structuring of implants due to the possibility of creating surfaces with a wide variety of nano- and microstructures. To achieve a desired surface topography, different laser structuring parameters can be adjusted. The scanning strategy, or rather the laser pulse overlap and scanning line overlap, affect the surface topography in an essential way, which is demonstrated in this study. Ti6Al4V samples were structured using a 300 fs laser source with a wavelength of 1030 nm. Laser pulse overlap and scanning line overlap were varied between 40% and 90% over a wide range of fluences (F from 0.49 to 12.28 J/cm²), respectively. Four different main types of surface structures were obtained depending on the applied laser parameters: femtosecond laser-induced periodic surface structures (FLIPSS), micrometric ripples (MR), micro-craters, and pillared microstructures. It could also be demonstrated that the exceedance of the strong ablation threshold of Ti6Al4V strongly depends on the scanning strategy. The formation of microstructures can be achieved at lower levels of laser pulse overlap compared to the corresponding value of scanning line overlap due to higher heat accumulation in the irradiated area during laser machining.

Sign in / Sign up

Export Citation Format

Share Document