1,721,045 research outputs found
Burst mode versus single-pulse machining for Bessel beam micro-drilling of thin glass: study and comparison
No full textEtching and drilling of through-holes in thin glass by means of picosecond Bessel beams
No full textIn this paper, we present a laser etching and drilling technique for thin glass materials based on the use of finite-energy pulsed Bessel beams orthogonally impinging on the sample surface. Thanks to the elongated focal zone of the quasinon-diffractive beam, the laser processing can be performed without scanning the beam position along the thickness of the transparent material sample, but simply moving the sample in the plane orthogonal to the beam. We first present the results of single-shot glass microfabrication performed to identify the optimal laser parameters needed for an efficient internal material ablation. We then describe the micromachining technique used for etching the dielectric material at glass-air interfaces and for generating, without chemical etching, through-holes in thin glasses
Ultrafast Laser Micromachining in Crystals Using Bessel Beams
No full textUltrafast laser micromachining in bulk diamond and sapphire has been realized using finite energy Bessel-Gauss beams. The hardness of diamond and crack formation in sapphire have been addressed and tackled using different optimization techniques
Paraxial envelope X waves
No full textA report on the existence of luminal, localized and exactly invariant X-type solutions of paraxial wave equation in dispersive media was presented. It was observed that the eX waves play a significant role in the description of recent nonlinear, paraxial experiments with X-type pulses. It was found that the characteristics of localization and stationarity in normally dispersive media closely resemble those of self-generated X-type pulses in second-harmonic generation processes
X-waves in self-focusing of ultra-short pulses
No full textX waves are emerging as a universal concept that allows us to interpret experiments of filamentation and trapping in a normally dispersive medium. We briefly review the main experimental and theoretical results behind this paradigm
Experimental energy-density flux characterization of ultrashort laser pulse filaments
No full textVisualization of the energy density flux gives a unique insight
into the propagation properties of complex ultrashort pulses. This analysis,
formerly relegated to numerical investigations, is here shown to be an
invaluable experimental diagnostic tool. By retrieving the spatio-temporal
amplitude and phase we experimentally obtain the energy density flux
within complex ultrashort pulses generated by filamentation in a nonlinear
Kerr medium
Plasma absorption evidence via chirped pulse spectral transmission measurements of a bessel beam propagating in glass
No full textDemonstration of spontaneously generated conical waves during ultrashort laser pulse filamentation in air
No full textMeasurements and simulations show that X-waves are spontaneously generated during filamentation in air. This explains the sub-diffractive propagation of filaments beyond the end of the plasma channel generated by multiphoton ionization. © 2008 Optical Society of America
Colored conical emission by means of second-harmonic generation
No full textNonlinear optical media that are normally dispersive support a new type of localized (nondiffractive and nondispersive) wave packets that are X shaped in space and time and have slower than exponential decay. High-intensity X waves, unlike linear ones, can be formed spontaneously through a trigger mechanism of conical emission, thus playing an important role in experiments
Dynamics of Bessel beam induced graphitization of diamond: exploring the role of in-bulk plasma
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