Search results for "Laser pulses"
showing 4 items of 4 documents
Spatiotemporal light-beam compression from nonlinear mode coupling
2017
We experimentally demonstrate simultaneous spatial and temporal compression in the propagation of light pulses in multimode nonlinear optical fibers. We reveal that the spatial beam self-cleaning recently discovered in graded-index multimode fibers is accompanied by significant temporal reshaping and up to four-fold shortening of the injected sub-nanosecond laser pulses. Since the nonlinear coupling among the modes strongly depends on the instantaneous power, we explore the entire range of the nonlinear dynamics with a single optical pulse, where the optical power is continuously varied across the pulse profile.
Interference Effects in Photodetachment of F- in a Strong Circularly Polarized Laser Pulse
2007
A numerical simulation of photodetachment of F{sup -} by a circularly polarized laser pulse has been accomplished by using a Keldysh-type approach. The numerical results are in agreement with measurements of photoelectron energy spectra recently reported in the literature. The features exhibited by the spectra are traced back to quantum interference effects, in the same spirit as in a double-slit experiment in the time doma0008.
Non-linear interactions of femtosecond laser pulses with graphene : photo-oxidation, imaging and photodynamics
2017
This thesis presents a study focused on interactions of femtosecond laser pulses with graphene, a one atom thick carbon membrane. Graphene, which exhibits exceptional electronic and optoelectronic properties, could provide considerable advantage over current silicon-based electronics. Graphene alone, being semi-metal, is not sufficient for electronic applications, but requires modification. For this, a set of methods for modifying and measuring the properties of graphene was developed. With the perspective of making graphene a suitable component for electronics, optoelectronics or photonics, ultrashort laser pulses were used for drawing patterns on graphene. The procedure modifies graphene …
Chronic neuropathic facial pain after intense pulsed light hair removal. Clinical features and pharmacological management
2015
Intense Pulsed Light (IPL) photodepilation is usually performed as a hair removal method. The treatment is recommended to be indicated by a physician, depending on each patient and on its characteristics. However, the use of laser devices by medical laypersons is frequent and it can suppose a risk of damage for the patients. Most side effects associated to IPL photodepilation are transient, minimal and disappear without sequelae. However, permanent side effects can occur. Some of the complications are laser related but many of them are caused by an operator error or mismanagement. In this work, we report a clinical case of a patient that developed a chronic neuropathic facial pain following…