Pump-probe microscopy of tailored ultrashort laser pulses for glass separation processes

In‐Volume Laser Direct Writing of Silicon—Challenges and Opportunities

“…[ 68–70 ] Given that dielectrics are transparent to visible light which can be sensed with standard silicon‐based detectors, various pump‐probe methods have been applied during the last decades to experimentally access all dynamical aspects from ionization, trapping of generated free‐carriers to material responses. [ 51,68–76 ] This metrology is progressively translated in the infrared to allow similar measurements inside silicon and other narrow‐gap semiconductors. [ 13,77,78 ] While the resolution limit obviously decreases with long wavelengths, by using InGaAs array sensors and microscopy arrangements optimized at telecommunication wavelengths (e.g., 1.3 or 1.55 m), one can reach enough precision to extract the free‐carrier density and the spatial distribution of the laser‐induced microplasmas produced by tightly focused femtosecond pulses.…”

Beam shaping for ultrafast materials processing

“…Although the transverse intensity profile of higher-order Bessel-like beams completely differ from the zero order version, the above mentioned remarkable properties of 11,37,38 Such intensity distributions/beam shaping approaches show promising prospects for material modifications and processing, e.g., the precise cutting of glass 11,35,39 by making targeted use of crack formations. 31,40 We verify excellent suitability of this class of beams for transparent materials processing using a time resolved tomographic imaging concept, see Bergner et al, 11 which allows to reconstruct the three-dimensional spatial distribution of the transient extinction coefficient κ (r). § This enables to directly measure the material's absorbing response ¶ caused by the ultrashort pulse and, thus, to analyze where energy was deposited.…”

“…Fig. 11 (c)] which was recorded using pump-probe microscopy (see Jenne et al 40 for experimental details about the diagnostic tool). A single laser burst with 4 pulses (pulse energy of 30 µJ) emitted from a TruMicro 2000 with a pulse duration of 5 ps was used.…”

High‐Power Laser Systems

“…The peak power of megawatt-class lasers is mainly used in material processing, [1][2][3][4][5] including surface structuring [6,7] and cleaving of glass. [8][9][10][11] The peak power of gigawatt-class lasers produces isolated attosecond extreme-ultraviolet pulses using high harmonic generation. It is a key technology for analyzing ultrafast electronic phenomena in attosecond physics.…”