Himansu Shekhar Pradhan

Suppression of stimulated Brillouin scattering using optimization techniques

The Stimulated Brillouin Scattering (SBS) suppression using optimisation techniques and its effect on performance improvement on long range fiber based Distributed system is analyzed in this paper. This paper presents the suppression of stimulated Brillouin scattering by increasing the SBS threshold power using phase modulation and fiber optimization technique.

Brillouin Distributed Temperature Sensor Using Optical Time Domain Reflectometry Techniques

This paper presents the performance improvement of Brillouin distributed temperature sensor (BDTS) using deconvolution algorithm. We have analysed three different OTDR techniques in terms of spatial resolution improvement using Fourier regularized deconvolution (FourRD) algorithm. The effects of coherent Rayleigh noise (CRN) on temperature and spatial resolution of the above system are being investigated. In this paper, using a light source of power 10 mW and 400 ns pulse widths; a spatial resolution of 25 and 20 m is observed for a pseudorandom coded BOTDR in the presence and absence of CRN respectively. Similarly, in case of conventional BOTDR and coherent BOTDR system in the presence of CRN, the spatial resolutions observed are 40 and 35 m respectively. Numerical simulation results indicate that the pseudorandom coded BOTDR is a better candidate for design of BDTS in terms of spatial resolution as compared to the other two schemes as discussed above.

SNR Enhancement of Brillouin Distributed Strain Sensor Using Optimized Receiver

This paper presents an improvement on signal to noise ratio (SNR) of long range Brillouin distributed strain sensor (BDSS). Differential evolution (DE) algorithm is used for receiver (avalanche photo diode (APD)) optimization. We have extracted the strain information of the proposed sensor using Fourier deconvolution algorithm and Landau Placzek ratio (LPR). SNR of the proposed system is realized using Indium Gallium Arsenide (InGaAs) APD detector over 50 km sensing range. We have achieved about 30 dB improvement of SNR using optimized receiver compared to non-optimized receiver at 25 km of sensing distance for a launched power of 10 mW. The strain resolution is observed as 1670\({\mu\varepsilon}\) at a sensing distance of 50 km. Simulation results show that the proposed strain sensor is a potential candidate for accurate measurement of strain in sharp strain variation environment.

A survey on the performances of distributed fiber-optic sensors

This paper presents a survey on distributed fiber-optic sensors (DFOS) and their performances features. Distributed fiber optic sensors are becoming increasingly popular for long range sensing applications such as monitoring temperature in hydrocarbon supply lines (oil and gas pipeline), structural health monitoring of civil structures, strain monitoring of dam and bridges etc. Moreover, these sensors are embedded with the composite materials for realtime estimation of temperature and strain vibration in civil structures. Nowadays, a lot of research is going on the development of distributed fiber-optic sensor and many are commercialized by several industries. We have made a survey on fiber-optic distributed sensors using scattering principles as well as their performances such as sensing accuracy, sensing resolution, sensing range and spatial resolution for different sensing applications.

Brillouin distributed strain sensor performance enhancement employing FourWaRD algorithm

The improvement of strain and spatial resolution of Brillouin distributed strain sensor using Fourier wavelet regularized deconvolution is reported. The proposed system allows strain sensing upto 50km with strain and spatial resolution 300𝜇e and 7m.

Performance Enhancement of Brillouin Distributed Temperature Sensor Using Optimized Fiber

The improvement of signal-to-noise ratio (SNR) and the suppression of stimulated Brillouin scattering (SBS) effects in a long-range distributed sensor are presented in this paper. We have designed a simple Brillouin distributed temperature sensor using phase modulation and optimization technique. Global evolutionary computing-based optimization technique [particle swarm optimization (PSO)] is applied for fiber and receiver optimization. The simulated results of the sensing system are reported in this paper. The combination of phase modulation and the global evolutionary computing technique improved the SBS threshold power to an extent of 6.8 and 6.3 dBm for 50 and 75 km of sensing range, respectively. However, with both receiver and fiber optimization, a 20 dBm improvement of SNR for an input power of 5 dBm and 75 km of sensing range is reported.