scholarly journals Intensity and Wavelength Division Multiplexing FBG Sensor System Using a Raman Amplifier and Extreme Learning Machine

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yibeltal Chanie Manie ◽  
Run-Kai Shiu ◽  
Peng-Chun Peng ◽  
Bao-Yi Guo ◽  
Mekuanint Agegnehu Bitew ◽  
...  

A fiber Bragg grating (FBG) sensor is a favorable sensor in measuring strain, pressure, vibration, and temperature in different applications, such as in smart structures, wind turbines, aerospace, industry, military, medical centers, and civil engineering. FBG sensors have the following advantages: immune to electromagnetic interference, light weight, small size, flexible, stretchable, highly accurate, longer stability, and capable in measuring ultra-high-speed events. In this paper, we propose and demonstrate an intensity and wavelength division multiplexing (IWDM) FBG sensor system using a Raman amplifier and extreme learning machine (ELM). We use an IWDM technique to increase the number of FBG sensors. As the number of FBG sensors increases and the spectra of two or more FBGs are overlapped, a conventional peak detection (CPD) method is unappropriate to detect the central Bragg wavelength of each FBG sensor. To solve this problem, we use ELM techniques. An ELM is used to accurately detect the central Bragg wavelength of each FBG sensor even when the spectra of FBGs are partially or fully overlapped. Moreover, a Raman amplifier is added to a fiber span to generate a gain medium within the transmission fiber, which amplifies the signal and compensates for the signal losses. The transmission distance and the sensing signal quality increase when the Raman pump power increases. The experimental results revealed that a Raman amplifier compensates for the signal losses and provides a stable sensing output even beyond a 45 km transmission distance. We achieve a remote sensing of strain measurement using a 45 km single-mode fiber (SMF). Furthermore, the well-trained ELM wavelength detection methods accurately detect the central Bragg wavelengths of FBG sensors when the two FBG spectra are fully overlapped.

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7355
Author(s):  
Amare Mulatie Dehnaw ◽  
Yibeltal Chanie Manie ◽  
Ya Yu Chen ◽  
Po Han Chiu ◽  
Hung Wei Huang ◽  
...  

The focus of this paper was designing and demonstrating bus structure FBG sensor networks using intensity wavelength division multiplexing (IWDM) techniques and a gated recurrent unit (GRU) algorithm to increase the capability of multiplexing and the ability to detect Bragg wavelengths with greater accuracy. Several Fiber Bragg grating (FBG) sensors are coupled with power ratios of 90:10 and 80:10, respectively in the suggested experimental setup. We used the latest IWDM multiplexing technique for the proposed scheme, as the IWDM system increases the number of sensors and allows us to alleviate the limited operational region drawback of conventional wavelength division multiplexing (WDM). However, IWDM has a crosstalk problem that causes high-sensor signal measurement errors. Thus, we proposed the GRU model to overcome this crosstalk or overlapping problem by converting the spectral detection problem into a regression problem and considered the sequence of spectral features as input. By feeding this sequential spectrum dataset into the GRU model, we trained the GRU system until we achieved optimal efficiency. Consequently, the well-trained GRU model quickly and accurately identifies the Bragg wavelength of each FBG from the overlapping spectra. The Bragg wavelength detection performance of our proposed GRU model is tested or validated using different numbers of FBG sensors, such as 3-FBG, 5-FBG, 7-FBG, and 10-FBG, separately. As a result, the experiment result proves that the well-trained GRU model accurately identifies each FBG Bragg wavelength, and even the number of FBG sensors increase, as well as the spectra of FBGs, which are partially or fully overlapped. Therefore, to boost the detection efficiency, reliability, and to increase the multiplexing capabilities of FBG sensor networks, the proposed sensor system is better than the other previously proposed methods.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Bentahar Attaouia ◽  
Kandouci Malika ◽  
Ghouali Samir

AbstractThis work is focused to carry out the investigation of wavelength division multiplexing (WDM) approach on free space optical (FSO) transmission systems using Erbium Ytterbium Doped Waveguide Amplifier (EYDWA) integrated as post-or pre-amplifier for extending the reach to 30 Km for the cost-effective implementation of FSO system considering weather conditions. Furthermore, the performance of proposed FSO-wavelength division multiplexing (WDM) system is also evaluated on the effect of varying the FSO range and results are reported in terms of Q factor, BER, and eye diagrams. It has been found that, under clear rain the post-amplification was performed and was able to reach transmission distance over 27 Km, whereas, the FSO distance has been limited at 19.5 Km by using pre-amplification.


2019 ◽  
Vol 0 (0) ◽  
Author(s):  
I. S. Amiri ◽  
Fatma Mohammed Aref Mahmoud Houssien ◽  
Ahmed Nabih Zaki Rashed ◽  
Abd El-Naser A. Mohammed

AbstractThe 16-channels dense wavelength division multiplexing (DWDM) systems have been optimized by utilizing hybrid configurations of conventional optical fiber amplifiers (EDFA, RAMAN and SOA) and optical photodetectors (PIN, APD(Si) and APD(InGaAs)). The DWDM systems were implemented for 5 Gb/s channel speed using one of these configurations with 100 GHz channel spacing and 25 km amplifying section. The hybrid configurations are the combinations of (PIN + EDFA), (PIN + RAMAN), (PIN + SOA), (APD(Si) + EDFA), (APD(Si) + RAMAN), (APD(Si) + SOA), (APD(InGaAs) + EDFA), (APD(InGaAs) + RAMAN) and (APD(InGaAs) + SOA). Based on BER, Q-factor and eye diagrams, the performance was compared for these configurations under influences of various thermal noise levels of photodetectors over different fiber lengths ranging from 25 km up to 150 km. The results revealed that both APD structures give optimum performance at input power Pin = 5 dBm due to high internal avalanche gain. EDFA outperforms RAMAN and SOA amplifiers. SOA amplifier shows degraded performance because of nonlinearity effects induced. RAMAN amplifier seems to be the best alternative for long reach DWDM systems because it minimizes the effects of fiber nonlinearities. The configuration (APD(Si) + EDFA) is the most efficient and recommended to be used for transmission distance beyond 100 km due to its larger Q-factor.


2019 ◽  
Vol 40 (4) ◽  
pp. 341-346
Author(s):  
Kulwinder Singh ◽  
Karan Goel ◽  
Kamaljit Singh Bhatia ◽  
Hardeep Singh Ryait

Abstract Different fiber amplifiers such as semiconductor optical amplifier, erbium-doped fiber amplifier and erbium ytterbium-co-doped fiber amplifier (EYCDFA) are investigated for 16×40 GB/s wavelength division multiplexing system. Various performance parameters including Q-factor, bit error rate, jitter, eye opening and eye closure are observed and analyzed. It is reported that EYCDFA is a better choice among the tested amplifiers. The proposed system is also investigated in terms of transmission distance.


2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Meet Kumari ◽  
Reecha Sharma ◽  
Anu Sheetal

AbstractNowadays, bandwidth demand is enormously increasing, that causes the existing passive optical network (PON) to become the future optical access network. In this paper, next generation passive optical network 2 (NG-PON2) based, optical time division multiplexing passive optical network (OTDM-PON), wavelength division multiplexing passive optical network (WDM-PON) and time & wavelength division multiplexing passive optical network (TWDM-PON) systems with 20 Gbps (8 × 2.5 Gbps) downstream and 20 Gbps (8 × 2.5 Gbps) upstream capacity for eight optical network units has been proposed. The performance has been compared by varying the input power (−6 to 27 dBm) and transmission distance (10–130 km) in terms of Q-factor and optical received power in the presence of fiber noise and non-linearities. It has been observed that TWDM-PON outperforms OTDM-PON and WDM-PON for high input power and data rate (20/20 Gbps). Also, TWDM-PON shows its superiority for long-reach transmission up to 130 km, which is a cost-effective solution for future NG-PON2 applications.


2018 ◽  
Vol 0 (0) ◽  
Author(s):  
◽  
Chakresh Kumar

AbstractIn this paper we have study the performance of different optical amplifiers (Erbium doped amplifier (EDFA), RAMAN amplifier, and semiconductor optical amplifier (SOA)) for 80 channels wavelength division multiplexing (WDM) system with the data rate at 10 Gbps data rate for the transmission distance of 280 km After getting the results of these amplifiers the performance of these has to be compared The Q-factor values achieved better in EDFA as compared to SOA and RAMAN. While the BER getting good in SOA as compared with other amplifiers but in EDFA after 200 km it goes saturated, the Power achieved at the power estimator is getting better in EDFA optical amplifier while in other amplifier it achieved negative. At the end it is also study the Power with frequency in THz and the Eye Diagram of such amplifiers results.


2011 ◽  
Vol 109 ◽  
pp. 79-83 ◽  
Author(s):  
Hyung Joon Bang ◽  
Soo Hyun Kim

This paper introduces a FBG (fiber Bragg grating) based AE (acoustic emission) sensing system for use in health monitoring of composite wind turbine blades. In this study, a multiplexing high speed FBG sensor system was developed with a spectrometer-type demodulator based on a linear photo detector. Pencil break test was performed using an FBG sensor and the results were compared with the results of piezo-based AE sensor. For the performance test of fracture sensing in composite materials, a down-scaled wind turbine blade was fabricated and drop impact tests were performed. Arrayed 4 FBG sensors were installed in the skin of wind turbine blade and impacts of 15 J energy were applied by a drop weight. The frequency characteristics of impact induced AE signals were examined with short-time Fourier transform focused on the leading waves. Finally, the onset of fractures in composite structure was successfully assessed using arrayed FBG sensors.


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