Division Multiplexing Fiber Bragg Grating Research Articles

Frequency Division Multiplexing Fiber Bragg Grating Sensing System Based on a Dual-Loop Optoelectronic Oscillator

Frequency Division Multiplexing Fiber Bragg Grating Sensing System Based on a Dual-Loop Optoelectronic Oscillator

Silicon-microring-based interrogator for TDM-FBG sensors enabled by pulse compression.

We propose a silicon microring resonator (MRR)-based high-resolution interrogator enabled by novel slope-assisted filtering and pulse compression technology for time division multiplexed fiber Bragg grating (TDM-FBG) sensors. Golay coded optical pulses are launched into an FBG sensor array to produce a series of reflected pulses with different time delays due to various transmission distances. A tunable MRR filter is used for interrogation of all FBG sensors by direct detection and subsequent signal processing. As a proof of concept, a strain sensing experiment is conducted using a 2×1 TDM-FBG sensor array. The performance of the proposed interrogation system is evaluated experimentally, and the dynamic strain resolution can be as high as 20nε/Hz.

Simulative Study of Wavelength Division Multiplexing Fiber Bragg Grating in Nuclear Reactors Monitoring

The technologies of wavelength division multiplexing (WDM) have been theoretically studied and analyzed for multiplexing fiber Bragg grating (FBG) in a single optical fiber. This method allows a single fiber to carry many of identical FBGs, making this sensor more appropriate in the nuclear reactors. The analysis demonstrates that the multiplexing capacity can be incredibly enhance small data rates and high channel spacing. The interference effect among FBGs multi-reflections channels must be taken into account. This paper simulate WDM based FBG for a channel spacing of 0.1, 0.3, 0.5, 0.8, 1 nm Gaussian apodized FBGs at data rates of 2.5, 10, 40,100,160, 250 Gb/s respectively for nuclear applications. All simulations were performed in Optisystem software.

Integrated Dynamic Wavelength Division Multiplexed FBG Sensor Interrogator on a Silicon Photonic Chip

A wavelength division multiplexed fiber Bragg grating (FBG) sensor interrogator using an integrated unbalanced Mach–Zehnder interferometer followed by an arrayed waveguide grating on silicon-on-insulator platform is presented. The Bragg wavelength shift is determined through the phase-generated carrier demodulation technique, allowing accurate dynamic FBG interrogation. The performance of the proposed device was validated by comparing the measurements with a commercial FBG readout unit based on a spectrometer, serving as a reference. Experimental results demonstrate a dynamic strain resolution of 4.56 nϵ/√Hz and minimum detectable strain down to ∼0.49 μ ϵ at 1-kHz bandwidth.

Wavelength Division Multiplexed Fiber Bragg Grating Vibration Sensor Array with Temperature Compensation

We have developed a novel method of wavelength division multiplexed operation of thermally stabilized fiber Bragg grating (FBG) vibration sensors in that simultaneous multipoint vibration detection with a temperature-insensitive operation can be achieved. One of the sensing elements of the arrayed sensors consists of a pair of FBGs, one is used for providing a narrow-spectrum light from a broad-spectrum incoherent optical source and the other is used for vibration sensing. The paired FBG configuration enables us to compensate the temperature effects that are commonly applied to the FBGs used. In the experiment, two sensing elements are arranged in tandem and the detection of simultaneous two-point multiple vibrations and the measurement of an elastic wave propagating in a metal bar are demonstrated.