Wavelength division multiplexing devices with high-wavelength shift tolerance and their applications in broadband network communication applications

1996 ◽  
Author(s):  
Guoda Xu ◽  
Freddie S. Lin ◽  
John M. Bartha ◽  
Tomasz P. Jannson
Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 296
Author(s):  
Weibing Gan ◽  
Shiyu Tu ◽  
Yuan Tao ◽  
Lingyun Ai ◽  
Cui Zhang ◽  
...  

In this paper, we proposed and experimentally demonstrated an opto-mechatronics system to detect the micro-deformation of tracks caused by running trains. The fiber Bragg grating (FBG) array acting as sensing elements has a low peak reflectivity of around −40 dB. The center wavelengths were designed to alternate between 1551 nm and 1553 nm at 25 °C. Based on dual-wavelength, wavelength-division multiplexing (WDM)/time-division multiplexing (TDM) hybrid networking, we adopted optical time-domain reflectometry (OTDR) technology and a wavelength-scanning interrogation method to achieve FBG array signal demodulation. The field experimental results showed that the average wavelength shift of the FBG array caused by the passage of the lightest rail vehicle was −225 pm. Characteristics of the train-track system, such as track occupancy, train length, number of wheels, train speed, direction, and loading can be accurately obtained in real time. This opto-mechatronics system can meet the requirements of 600 mm spatial resolution, long distance, and large capacity for monitoring the train-track system. This method exhibits great potential for applications in large-scale train-track monitoring, which is meaningful for the safe operation of rail transport.


2013 ◽  
Vol 718-720 ◽  
pp. 636-640
Author(s):  
Fang Dong Zhu ◽  
Dong Sheng Zhang ◽  
Yong Xing Guo ◽  
Li Tong Li

A fiber Bragg grating (FBG) sensing network for vibration measurement is proposed and demonstrated in this paper. The light source of the described sensing technique is an erbium-doped fiber laser applying a 980-nm laser diode and a fiber Fabry-Perot tunable filter. The fiber laser has a 40nm tuning range, allowing many vibration sensors to be multiplexed on the same fiber. Reflected light wavelength shift of the FBG sensor caused by strain variation is converted to intensity deviation, which avoids a complex demodulation process. This sensing scheme can effectively increase the demodulation speed of sensing system up to 20 KHz. At least 20 FBGs can be multiplexed alone a fiber.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Dingding Zhang ◽  
Chenyang Ma ◽  
Yanyan Duan ◽  
Wengang Du ◽  
Jinxuan Liu ◽  
...  

Real-time monitoring of settlement and deformation within a coal mine’s deep quaternary unconsolidated strata presents challenges with installation and signal analysis. This paper presents results from successfully installing a field-scale fiber Bragg grating (FBG) sensing system in a deep borehole for the purpose of achieving real-time monitoring of the settlement and deformation in a deep unconsolidated stratum. A 152 m deep by 133 mm diameter borehole was used to embed an array of 24 FBG sensors in 12 layers of gravel and clay from between 92.4 m and 148.7 m of unconsolidated quaternary strata. A wavelength bandwidth of ±4.5 nm was used with a wavelength division multiplexing and spatial division multiplexing technique to compose a 4-by-6 sensor array. During the four stages of installation, the real-time transmission characteristics and the changes in the FBG wavelength for this sensing system were evaluated. While the FBG sensing system was stable after installation, it was clearly shown that the engineering techniques associated with both positioning and grouting influenced the mechanical properties and transmission characteristics of the system. After installation, the sensor survival rate was found to be 78.26% with a maximum FBG wavelength shift of 1.447 nm. This field-scale installation has provided information and experience that will improve future installations of buried fiber optic sensing technology throughout the underground coal mine industry.


2019 ◽  
Vol 40 (4) ◽  
pp. 423-428
Author(s):  
HoangViet Nguyen

Abstract We have proposed and demonstrated a novel architecture to implement in Coarse Wavelength-Division-Multiplexing (CWDM) technologies to give integrated broadband services for residential complex use system. For keeping the speed of 1000 Mbps at the bus IFs, CWDM technology is employed, and eight wavelengths are allocated to eight bus IFs, respectively. We also have evaluated characteristics of the transmission by calculated and measured the throughputs. The optical IP network can be easy in-service by adjusting the number of wavelengths and optical transceivers. We believe this novel scheme can be applied for future broadband network.


Author(s):  
BHADRA ANAMIKA ◽  
SAHU VIKAS ◽  
SHRIVASTAVA SHARAD MOHAN ◽  
ANSHU ◽  
SANGHVI ANJALI S. ◽  
...  

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