Echo, Reverberation, and Echo-to-Reverberation Ratio for a Short Pulse in a Range-Dependent Pekeris Waveguide

2017 ◽  
Vol 42 (2) ◽  
pp. 362-372 ◽  
Author(s):  
Michael A. Ainslie ◽  
Dale D. Ellis
2017 ◽  
Vol 187 (11) ◽  
pp. 1280-1287 ◽  
Author(s):  
Leonid V. Keldysh

2013 ◽  
Vol 20 (2) ◽  
pp. 183-190 ◽  
Author(s):  
A. Barna ◽  
I. B. Földes ◽  
Z. Gingl ◽  
R. Mingesz

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/).


Author(s):  
F. Beaudoin ◽  
P. Perdu ◽  
C. DeNardi ◽  
R. Desplats ◽  
J. Lopez ◽  
...  

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.


2020 ◽  
Vol 110 (11-12) ◽  
pp. 787-789
Author(s):  
Marcel Simons ◽  
Till Rusche ◽  
Tobias Valentino ◽  
Tim Radel ◽  
Frank Vollertsen

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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