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The preliminary numerical simulation results obtained in the analysis of a landmine detection system based on laser excitation of acoustic -seismic waves in the soil and observing its surface vibration above the embedded landmine are presented. The presented numerical simulations comprise three main parts: 1) Laser oscillator and laser beam propagation and absorption in soil; a laser oscillator operated in Q-switched regime is considered; different laser wavelengths are investigated. 2) Acoustic -seismic wave generation by absorption in soil of laser pulse energy; 3) Evaluation of acoustic -seismic wave generation by the buried in soil landmine; 4) Comparison of Distributed FeedBack Fiber Laser (DFB-FL) and Laser Doppler Vibrometer (LDV) detector used for soil vibrations evaluation. The above mentioned numerical simulation is dedicated for evaluation of an integrated portable detection system.

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Results obtained by FEM analysis of a smart mechanical part manufactured of reinforced composite materials with embedded long period grating fiber sensors (LPGFS) used for operation monitoring are presented. Fiber smart reinforced composite materials because of their fundamental importance across a broad range of industrial applications, as aerospace industry. The main purpose of the performed numerical analysis consists in final improved design of composite mechanical components providing a feedback useful for further automation of the whole system. The performed numerical analysis is pointing to a correlation of composite material internal mechanical loads applied to LPGFS with the NIR absorption bands peak wavelength shifts. One main idea of the performed numerical analysis relies on the observed fact that a LPGFS embedded inside a composite material undergoes mechanical loads created by the micro scale roughness of the composite fiber network. The effect of this mechanical load consists in bending of the LPGFS. The shifting towards IR and broadening of absorption bands appeared in the LPGFS transmission spectra is modeled according to this observation using the coupled mode approach.

Various aspects of distributed feedback fiber laser sensors, their interaction with environment and their possible applications are investigated by numerically solving coupled-mode equations system describing the laser field propagation. The developed numerical analysis has the aim to better understand the DFB-FL itself and its interaction with environment in order to be operated as a sensor. The main idea consists in finding out how various environment parameters modify the coefficients of coupled-mode equations describing the laser field propagation through the DFB-FL structure.