laser spectroscopy; laser sensing; laser induced fluorescence; laser induced breakdown spectroscopy; chlorophyll A; fluorometer; ROV;LIBS; SPECTROMETER; SCIENCE

Laser technologies that are used for the development of sensor elements for Remotely Operated Vehicles (ROVs) are presented, as well as the latest developments in underwater robotics where laser spectroscopy methods are applied to environmental monitoring. A submersible laser spectrometer unit intended for studying Raman scattering and laser-induced fluorescence (LIF) spectra is presented. The spectrometer was developed as an element of an ROV sensor system for remote detection and measurements of organic matter concentrations in sea water and underwater objects. The results of environmental tests of the submersible LIF spectrometer in various marine areas, including the Arctic, are described.

Filament; AC Stark effect; Rabi sideband; Line broadening; Amplified spontaneous emission;INDUCED BREAKDOWN SPECTROSCOPY; SPECTRAL-LINES; RADIATION; SYSTEM

he temporal evolution of the width and shift of NI746.8 and OI777.4 nm lines is investigated in a filament plasma produced by a tightly focused femtosecond laser pulse (0.9 mJ, 48 fs). The nitrogen line shift and width are determined by the joint action of electron impact shift and the far-off resonance AC Stark effect. The intensive (I = 1.2.10(10) W/cm(2)) electric field of ASE (amplified spontaneous emission) and post-pulses result in a possible LS coupling break for the OI3p P-5 level and the generation of Rabi sidebands. The blueshifted main femtosecond pulse and Rabi sideband cause the stimulated emission of the N-2 1(+) system. The maximal widths of emission lines are approximately 6.7 times larger than the calculated Stark widths. (C) 2017 Elsevier B.V. All rights reserved.

Femtosecond; Laser repetition rate; Limit of detection;INDUCED BREAKDOWN SPECTROSCOPY; NANOSECOND

Experimentally investigated limit of detection Mg, Al, Sr, Pb. depending on the pulse repetition rate femtosecond Ti: Sa laser optical breakdown in aqueous solutions on the surface of the investigated element in the laser pulse duration 60 fs, pulse energy of 1 mJ. The study was conducted for the laser pulse repetition rate of 50 Hz, 150 Hz, 250 Hz. To choose the optimal time delay of registration relative to the laser beam for the following chemicals:: Na, N, Fe, Ca, Mg, Al, Pb, Mn.