Publications by authors named "Juri Agresti"

2 Publications

  • Page 1 of 1

High Energy Double Peak Pulse Laser Induced Plasma Spectroscopy for Metal Characterization Using a Passively Q-Switched Laser Source and CCD Detector.

Sensors (Basel) 2019 Aug 21;19(17). Epub 2019 Aug 21.

Istituto di Fisica Applicata "Nello Carrara"-CNR, 50019 Sesto Fiorentino, Italy.

Here, the development and testing of a portable double peak pulse laser induced plasma spectroscopy (DPP-LIPS) based on passively Q-switched Nd:YAG (Neodymium-doped Yttrium Aluminum Garnet) laser excitation is reported. The latter delivered structured laser pulses at a repetition rate of up to 20 Hz, including two energy peaks of about 100 mJ each with a relative temporal spacing of about 80 µs. Plasma spectra were collected using a low-cost Czerny-Turner spectrometer equipped with a non-intensified CCD (Charge-Coupled Device) array. Such a DPP-LIPS setup is technologically simpler and cheaper than the usual ones. Despite the relatively large temporal separation between the mentioned laser peaks, significant spectral intensity enhancements with respect to the usual single peak pulse configuration were observed. The amplification factor measured ranged between 2 and 10, depending on the specific emission peaks and the Q-switched configuration, and a consequent significant improvement of the detection limit of trace elements was observed. The instrument was calibrated for the quantitative analysis of copper alloy through systematic measurements carried out on reference samples and was then tested in an example archaeometric characterization of a statuette from the Egyptian Museum of Florence.
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http://dx.doi.org/10.3390/s19173634DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6749410PMC
August 2019

Duality relation between nonspherical mirror optical cavities and its application to gravitational-wave detectors.

J Opt Soc Am A Opt Image Sci Vis 2012 Sep;29(9):1818-27

Istituto di Fisica Applicata Nello Carrara-CNR, Sesto Fiorentino (FI), Italy.

In this paper, we analytically prove a unique duality relation between the eigenspectra of paraxial optical cavities with nonspherical mirrors: a one-to-one mapping between eigenmodes and eigenvalues of cavities deviating from flat mirrors by h(r) and cavities deviating from concentric mirrors by -h(r), where h need not be a small perturbation. We then illustrate its application to optical cavities, proposed for advanced interferometric gravitational-wave detectors, where the mirrors are designed to support beams with rather flat intensity profiles over the mirror surfaces. This unique mapping might be very useful in future studies of alternative optical designs for advanced gravitational wave interferometers or experiments employing optical cavities with nonstandard mirrors.
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http://dx.doi.org/10.1364/JOSAA.29.001818DOI Listing
September 2012