Methodology for the conception of speckle reduction elements in the case of short pulse illumination

Abstract In experiments with short-pulse lasers the measurement control of the energy of the laser pulse is of crucial importance. Generally it is difficult to measure the amplitude of the pulses of short-pulse lasers using electronic devices, their response time being longer than the duration of the laser pulses. The electric response of the detector is still too fast to be directly digitized therefore a peak-hold unit can be used to allow data processing for the computer. In this paper we present a device which measures the energy of UV short (fs) pulses shot-byshot, digitizes and sends the data to the PC across an USB interface. The circuit is based on an analog peak detect and hold unit and the use of fiber optical coupling between the PC and the device provides a significant improvement to eliminate potential ground loops and to reduce conductive and radiated noise as well. The full development is open source and has been made available to download from our web page (http://www.noise.inf.u-szeged.hu/Instruments/PeakHold/).

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Ultra-Short Pulse Laser Ablation of Biological Hard Tissue and Biocompatibles

Journal of Laser Micro/Nanoengineering ◽

10.2961/jlmn.2008.01.0007 ◽

2008 ◽

Vol 3 (1) ◽

pp. 30-40 ◽

Cited By ~ 16

Author(s):

Martin Strassl

Keyword(s):

Laser Ablation ◽

Pulse Laser ◽

Pulse Laser Ablation ◽

Short Pulse ◽

Hard Tissue ◽

Short Pulse Laser ◽

Ultra Short Pulse ◽

Ultra Short Pulse Laser

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Silicon Thinning using Ultra-Short Pulse Laser Ablation

ISTFA 2004: Conference Proceedings from the 30th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2004p0552 ◽

2004 ◽

Author(s):

F. Beaudoin ◽

P. Perdu ◽

C. DeNardi ◽

R. Desplats ◽

J. Lopez ◽

...

Keyword(s):

Laser Ablation ◽

Sample Preparation ◽

Pulse Laser ◽

Pulse Laser Ablation ◽

Short Pulse ◽

Special Care ◽

Short Pulse Laser ◽

Ultra Short Pulse ◽

Ultra Short Pulse Laser

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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