Publication

Formation of nanogratings in a porous glass immersed in water by femtosecond laser irradiation

Yves Bellouard, Min Huang, Ya Cheng
2015
Article de conférence
Résumé

Irradiation of intense ultrafast laser pulses in glasses can lead to formation of nanogratings whose periods are significantly smaller than the incident irradiation wavelength. The mechanism of the exotic phenomenon is still under hot debate. Here, we access the snapshots of morphologies in the laser affected regions in a porous glass which reveal the evolution of the formation of nanogratings with increasing number of laser pulses. Combined with further theoretical analyses, our observation provides important clues which suggest that excitation of standing plasma waves at the interfaces between areas modified and unmodified by the femtosecond laser irradiation plays a crucial role for promoting the growth of periodic nanogratings. The finding indicates that the formation of volume nanogratings induced by irradiation of femtosecond laser pulses is initiated with a mechanism similar to the formation of surface nanoripples.

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Concepts associés (27)
Laser
thumb|250px|Lasers rouges (660 & ), verts (532 & ) et bleus (445 & ). thumb|250px|Rayon laser à travers un dispositif optique. thumb|250px|Démonstration de laser hélium-néon au laboratoire Kastler-Brossel à l'Université Pierre-et-Marie-Curie. Un laser (acronyme issu de l'anglais light amplification by stimulated emission of radiation qui signifie « amplification de la lumière par émission stimulée de radiation ») est un système photonique.
Pulsed laser
Pulsed operation of lasers refers to any laser not classified as continuous wave, so that the optical power appears in pulses of some duration at some repetition rate. This encompasses a wide range of technologies addressing a number of different motivations. Some lasers are pulsed simply because they cannot be run in continuous mode. In other cases the application requires the production of pulses having as large an energy as possible.
Ultrashort pulse
In optics, an ultrashort pulse, also known as an ultrafast event, is an electromagnetic pulse whose time duration is of the order of a picosecond (10−12 second) or less. Such pulses have a broadband optical spectrum, and can be created by mode-locked oscillators. Amplification of ultrashort pulses almost always requires the technique of chirped pulse amplification, in order to avoid damage to the gain medium of the amplifier. They are characterized by a high peak intensity (or more correctly, irradiance) that usually leads to nonlinear interactions in various materials, including air.
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Publications associées (57)

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