The influence of flying altitude, beam divergence, and pulse repetition frequency on laser pulse return intensity and canopy frequency distribution

2007 ◽  
Vol 33 (4) ◽  
pp. 312-324 ◽  
Author(s):  
Chris Hopkinson
Keyword(s):  
Laser Pulse ◽  
Frequency Distribution ◽  
Pulse Repetition Frequency ◽  
Repetition Frequency ◽  
Pulse Repetition ◽  
Beam Divergence

scholarly journals Impact of laser pulse repetition frequency on nucleation and growth of LiNbO3 thin films

2021 ◽  
pp. 2160019
Author(s):  
Z. Vakulov ◽  
D. Khakhulin ◽  
A. Geldash ◽  
R. V. Tominov ◽  
V. S. Klimin ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Pulse ◽  
Pulse Repetition Frequency ◽  
Green Energy ◽  
Repetition Frequency ◽  
Pulse Repetition ◽  
Physical Parameters ◽  
Energy Devices ◽  
Piezoelectric Energy ◽  
The Impact

This paper reports the impact of the laser pulse repetition frequency on growth processes, morphological and electro-physical parameters of nanocrystalline LiNbO3 thin films obtained by the pulsed laser deposition technique. It was found that the nucleation process in LiNbO3 films could controllably change by increasing the laser pulse repetition frequency. The film obtained at the repetition frequency of 4 Hz consists of local islands and clusters with a diameter of 118.1 ± 5.9 nm. Nanocrystalline films, grown at the repetition frequency of 10 Hz, possess a continuous granular structure with a grain diameter of 235 ± 11.75 nm. Achieved results can be used for the development of promising “green” energy devices based on lead-free piezoelectric energy harvesters.

Characteristic Structures on Film Induced by Femtosecond Laser Pulse Irradiation

2011 ◽  
Vol 179-180 ◽  
pp. 891-894
Author(s):  
Dong Qing Yuan ◽  
Jian Ting Xu
Keyword(s):  
Laser Pulse ◽  
Femtosecond Laser ◽  
Femtosecond Laser Pulse ◽  
Formation Mechanism ◽  
Pulse Repetition Frequency ◽  
Single Pulse ◽  
Repetition Frequency ◽  
Pulse Repetition ◽  
Pulse Irradiation ◽  
Cr Film

With femtosecond laser pulse (130 fs, 800 nm, 1 kHz pulse repetition frequency) irradiation on Au/Cr film stack, several nanostructures were obtained. The influence of laser parameters such as fluence(0.5J/cm2,2J/cm2) and the number of pulse were investigate. With single pulse irradiation, the nanoline and periodic ripple structures were obtained for the pulse fluence of 0.5J/cm2 and 2J/cm2, respectively. The formation mechanism of those nanostructures were discussed.

Relationship between damage to polymers and the laser pulse repetition frequency

1989 ◽  
Vol 19 (5) ◽  
pp. 673-675
Author(s):  
G Ya Glauberman ◽  
N F Pilipetskiĭ ◽  
S Yu Savanin ◽  
V V Shkunov
Keyword(s):  
Laser Pulse ◽  
Pulse Repetition Frequency ◽  
Repetition Frequency ◽  
Pulse Repetition

scholarly journals Effects of Non-thermal Ultrasound on a Fibroblast Monolayer Culture: Influence of Pulse Number and Pulse Repetition Frequency

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5040
Author(s):  
Silvia Ronda Peñacoba ◽  
Mar Fernández Gutiérrez ◽  
Julio San Román del Barrio ◽  
Francisco Montero de Espinosa
Keyword(s):  
Short Pulse ◽  
Pulse Repetition Frequency ◽  
Pulse Number ◽  
Repetition Frequency ◽  
Pulse Repetition ◽  
Treatment Protocols ◽  
Culture Plate ◽  
New Treatment ◽  
Long Pulse

Despite the use of therapeutic ultrasound in the treatment of soft tissue pathologies, there remains some controversy regarding its efficacy. In order to develop new treatment protocols, it is a common practice to carry out in vitro studies in cell cultures before conducting animal tests. The lack of reproducibility of the experimental results observed in the literature concerning in vitro experiments motivated us to establish a methodology for characterizing the acoustic field in culture plate wells. In this work, such acoustic fields are fully characterized in a real experimental configuration, with the transducer being placed in contact with the surface of a standard 12-well culture plate. To study the non-thermal effects of ultrasound on fibroblasts, two different treatment protocols are proposed: long pulse (200 cycles) signals, which give rise to a standing wave in the well with the presence of cavitation (ISPTP max = 19.25 W/cm2), and a short pulse (five cycles) of high acoustic pressure, which produces a number of echoes in the cavity (ISPTP = 33.1 W/cm2, with Pmax = 1.01 MPa). The influence of the acoustic intensity, the number of pulses, and the pulse repetition frequency was studied. We further analyzed the correlation of these acoustic parameters with cell viability, population, occupied surface, and cell morphology. Lytic effects when cavitation was present, as well as mechanotransduction reactions, were observed.

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