Micromachining of metals with ultra-short Ti-Sapphire lasers: Prediction and optimization of the processing time

Laser Beam MicroMachining (LBMM) – A review

“…In low fluence regime the optical penetration depth is 37.2 nm whereas for high fluence regime the electron diffusion length is 387 nm. Bruneel et al [111] investigated the processing time and ablation rate during the micromachining of copper and stainless steel of thickness 50 mm with different spatial profiles (top hat and Gaussian). It was observed that the processing time linearly reduce with the increase of laser repetition rate.…”

Float zone growth and anisotropic spectral properties of Nd:LaVO4 single crystals

“…Ultra-short pulse lasers are used in a variety of applications, such as ultra-fine processing and ultraprecise measurements [1][2][3][4]. For the mode lock type of short pulse laser, pulse duration is determined by the gain bandwidth of the laser medium on the basis of Heisenberg's uncertainty principle [5]; t  E  h/4 (1) where E is energy, t is time and h is Planck's constant.…”

“…Ti:sapphire is currently used as a gain medium for femtosecond lasers since it has a broad emission band from 700 nm to 900 nm, but it cannot be pumped with a commercially available laser diode (LD) [4,[6][7][8]. Accordingly, the present femtosecond laser system is very expensive and of large scale, and thus there has been an increasing interest in research for LD-pumped ultra-short pulse laser materials [9][10][11][12][13][14][15][16][17].…”

“…Nd:YVO 4 and Nd:GdVO 4 , are extensively investigated since they have large absorption and emission cross-sections; however, the fluorescence band widths of these materials are too narrow to achieve ultra-short pulse lasers of subpicosecond order [17][18][19][20][21][22][23][24][25][26]. In recent reports, it has been clarified that a host crystal that can provide Nd 3+ with a large substitution site shows a 3 broadened emission band [27,28].…”

“…After grinding, the powder was formed into a rod under a hydrostatic pressure of 100 MPa, and then sintered at 1200 ˚C for 10 h in air. 4 The crystals were grown in an image furnace with double ellipsoidal mirrors (NEC Machinery SC-N35HD-L), in which two halogen lamps of 1.5 kW were used as a heat source. Crystal growth was performed in the typical manner of the floating zone method [18][19][20][21][22][23][33][34][35][36][37].…”