Acta Photonica Sinica, Volume. 49, Issue 12, 34(2020)
FBG Demodulation Method Based on Frequency Shift Interference Digital Mixing Algorithm
Figures & Tables(12)
Fig. 2. Demodulating principle diagram of digital mixing method in modified FSI system
Table 1. Simulation results of Hilbert transformation
View tableView in ArticleTable 1. Simulation results of Hilbert transformation
Wavelength shift
Δλ/nm
Standard phase
difference/rad
Phase demodulation
difference/rad
Wavelength demodulation difference Δλ'/nm |Δλ-Δλ'|/nm 1 549.500~1 548.000 1.571 4.711 4.499 2.999 1 551.000~1 549.500 1.571 1.575 1.504 0.004 1 552.500~1 551.000 1.571 2.716 2.594 1.094 1 554.000~1 552.500 1.571 1.569 1.498 0.002
Table 2. Simulation results of digital mixing method
View tableView in ArticleTable 2. Simulation results of digital mixing method
Wavelength shift
Δλ/nm
Standard phase
difference/rad
Phase demodulation
difference/rad
Wavelength demodulation difference Δλ'/nm |Δλ-Δλ'|/nm 1 549.500~1 548.000 1.571 1.575 1.504 0.004 1 551.000~1 549.500 1.571 1.572 1.501 0.001 1 552.500~1 551.000 1.571 1.570 1.499 0.001 1 554.000~1 552.500 1.571 1.567 1.496 0.001
Table 3. Demodulation of adjacent phase difference by digital mixing method
View tableView in ArticleTable 3. Demodulation of adjacent phase difference by digital mixing method
Wavelength shift
Δλ/nm
Standard phase
difference/rad
Phase demodulation
difference/rad
Wavelength demodulation difference Δλ'/nm |Δλ-Δλ'|/nm 1 549.475~1 548.000 1.552 1.536 1.459 0.016 1 550.950~1 549.475 1.552 1.558 1.480 0.005 1 552.425~1 550.950 1.552 1.558 1.480 0.005 1 553.900~1 552.425 1.552 1.538 1.461 0.014
Table 4. Logic circuit characteristics of one-hot FSM phase compensation
View tableView in ArticleTable 4. Logic circuit characteristics of one-hot FSM phase compensation
Number of measurement groups Adjacent temperature
difference/℃
Fitting FBG wavelength
with temperature using spectrometer data/（pm·℃-1）
Hilbert transform demodulation
Wavelength variation with temperature/（pm·℃-1）
Demodulating wavelength with temperature by digital mixing/（pm·℃-1） 1 20.4~25.0℃（4.6℃） 26.4 28.3 25.2 2 25.0~30.5℃（5.5℃） 26.4 27.6 25.9 3 30.5~35.7℃（5.2℃） 26.4 27.5 26.8 4 35.7~40.2℃（4.5℃） 26.4 30.4 25.1 5 40.2~45.5℃（5.3℃） 26.4 26.6 24.4 6 45.5~50.5℃（5.0℃） 26.4 29.6 25.8 7 50.5~56.0℃（5.5℃） 26.4 23.8 25.0 8 56.0~60.0℃（4.0℃） 26.4 32.5 26.9 9 60.0~65.0℃（5.0℃） 26.4 29.0 26.5 10 65.0~70.0℃（5.0℃） 26.4 30.4 25.9
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Cong WEI, Ci-ming ZHOU, Xi CHEN, Yu-xiao LI, Han-jie LIU, Dian FAN. FBG Demodulation Method Based on Frequency Shift Interference Digital Mixing Algorithm[J]. Acta Photonica Sinica, 2020, 49(12): 34
Paper Information
Category: Fiber Optics and Optical Communications
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Published Online: Mar. 11, 2021
The Author Email: FAN Dian (fandian@whut.edu.cn)
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