Long-range microscopy of optically dense spray structures using Ultra-Short Pulse Off-Axis Digital Holography

Abstract Ultra-short pulse laser ablation is applied to IC backside sample preparation. It is contact-less, non-thermal, precise and can ablate the various types of material present in IC packages. This study concerns the optimization of ultra-short pulse laser ablation for silicon thinning. Uncontrolled silicon roughness and poor uniformity of the laser thinned cavity needed to be tackled. Special care is taken to minimize the silicon RMS roughness to less than 1µm. Application to sample preparation of 256Mbit devices is presented.

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UKP-laserbasierte Herstellung von Netzen unterschiedlicher Transmissionsgrade/USP-laser based production of meshes of different transmission degrees

wt Werkstattstechnik online ◽

10.37544/1436-4980-2020-11-12-51 ◽

2020 ◽

Vol 110 (11-12) ◽

pp. 787-789

Author(s):

Marcel Simons ◽

Till Rusche ◽

Tobias Valentino ◽

Tim Radel ◽

Frank Vollertsen

Keyword(s):

High Precision ◽

Processing Speed ◽

Laser Processing ◽

Short Pulse ◽

High Quality ◽

Mesh Width ◽

Variable Transmission ◽

Ultra Short Pulse ◽

Mesh Structures

Die Ultrakurzpuls (UKP)-laserbasierte Bearbeitung erlaubt die Herstellung von Netzstrukturen mit verschiedenen Transmissionsgraden. Vorteile der UKP-laserbasierten Herstellung der Netze liegen vor allem in der hohen Präzision und Bearbeitungsgeschwindigkeit. Die UKP-Laserbearbeitung ermöglicht die Herstellung von Netzen aus Aluminium in hoher Qualität, bezogen auf die Stegbreitenabweichung von < 8 µm, mit variablen Transmissionsgraden. Ultra-short pulse (USP) laser based processing enables the production of mesh structures with different degrees of transmission. The advantages of USP-based production of mesh structures are mainly the high precision and processing speed. USP laser processing enables the production of meshes of aluminum in high quality, with respect to the mesh width deviation of < 8 µm with variable transmission degrees.

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Laser Pulse Shortening via Zero-Dispersion Phase Matching of Parametric Raman Interactions in Crystals

Crystals ◽

10.3390/cryst11010019 ◽

2020 ◽

Vol 11 (1) ◽

pp. 19

Author(s):

Sergei N. Smetanin ◽

Michal Jelínek ◽

Dmitry P. Tereshchenko ◽

Mikhail N. Ershkov ◽

Václav Kubeček

Keyword(s):

Laser Pulse ◽

Short Pulse ◽

Matching Condition ◽

Phase Matching ◽

Dispersion Phase ◽

Birefringent Crystal ◽

Raman Lasers ◽

Birefringent Crystals ◽

Phase Matching Condition ◽

Ultra Short Pulse

We propose and study the conditions of zero-dispersion phase matching for parametric Raman interactions in birefringent crystals differing by anisotropy of zero-dispersion wavelength and allowing for the spectral tuning of the zero-dispersion phase-matching condition. We choose a highly birefringent crystal of calcite having a wide zero-dispersion anisotropy range for the demonstration of new effects of laser pulse shortening in parametric Raman lasers with spectrally tunable zero-dispersion phase matching. We demonstrate the anti-Stokes (1168 nm) and multi-Stokes (1629 nm) picosecond pulse shortening and self-separation of single 80-ps ultra-short pulse from the zero-dispersion phase-matched parametric Raman lasers that are based on the calcite crystal without using any electro-optical device.

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