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Pakanat Srijaroen 6105015 SCPY/B
Department of Physics, Faculty of Science, Mahidol University
Optical Fiber Bundle Displacement Sensors (OFBDS)
Application of OFBDS
1
Liquid level sensingThe sensing of surface roughness
OFBDS
Hang Zhou Yang. et al. (2014).
OFBDS
OutlinesIntroductionTheoretical modelSimulation
Experiment
Results
Discussion
Conclusion
2https://www.electronicsweekly.comhttps://global-sei.com/fttx/basicinfo/opticalfibernetworkwiringitems.html
Optical Fiber
3
Single fiber pair model
• Light source (S)
• Transmitting fiber (TF)
• Receiving fiber (RF)
• Photodetector (D)
Huimin Cao. et al. (2007).
4
Optical fiber bundle displacement sensors (OFBDS)
https://artphotonics.com/product/mid-ir-chalcogenide-and-polycrystalline-fiber-optic-bundles/
https://artphotonics.com/product/uv-vis-nir-silica-fiber-optic-bundles/
https://www.sqs-fiberoptics.com/high-power-laser-delivery-cable
5
Random (R)
Transmitting fiber (TF)
Receiving fiber (RF)
Concentric (C) Hemicircular (H)
Huimin Cao. et al. (2007).
Optical fiber bundle displacement sensors (OFBDS)
6
Hexagonal coordinates
(1,0)
(0,1)(-1,1)
(-1,0)
(0,-1) (1,-1)
(0,0)
(1,1)
(0,3)
Huimin Cao. et al. (2007).
Optical fiber bundle displacement sensors (OFBDS)
7
The distance between a and a is
Optical fiber bundle displacement sensors (OFBDS)
: center to center distance
Theoretical model
8
Single fiber pair model
Fiber bundle model
9
Single fiber pair modelTheoretical model :
Huimin Cao. et al. (2007).
Output light intensity distribution
• Light source (S)
• Transmitting fiber (TF)
• Receiving fiber (RF)
• Photodetector (D)
10
where : light power emitted from TF: effective radius of the output optical field
TFRF
Single fiber pair modelTheoretical model :
The intensity at the point is expressed by a modified Gauss function as
11
TFRF
Single fiber pair modelTheoretical model :
Note :
The intensity of reflected light ( )
???
11
TFRF
is the reflectivity of target surface
Single fiber pair modelTheoretical model :
Note :
The intensity of reflected light ( )
12
TFRF
Single fiber pair modelTheoretical model :
Note :
The intensity of reflected light ( )
is the reflectivity of target surface
13
Single fiber pair modelTheoretical model :
The received power is
pTF
RF
14
Single fiber pair modelTheoretical model :
The received power :
modulation function
: reflectivity of target surface
: light power emitted from TF
Theoretical model
15
Single fiber pair model
Fiber bundle model
16
Theoretical model : Fiber bundle model
The power received by the jth RF from the ith TF
The light power emitted from TF is
The total received power is
Theoretical model : Fiber bundle model
The total received power :
: distance between a and a
: reflectivity of target surface
: light power emitted from TF
: modulation function
17
modulation function :
18
Theoretical model : Fiber bundle model
Double circular (DC)
Concentric hemicircular (CH)
Concentric random (CR)
Hemicircular random (HR)
Transmitting fiber (TF)
Receiving fiber (RF)
DC CRCH HR
Huimin Cao. et al. (2007).
OFBDS with twin RF bundles
18
Theoretical model : Fiber bundle model
Double circular (DC)
Concentric hemicircular (CH)
Concentric random (CR)
Hemicircular random (HR)
Transmitting fiber (TF)
Receiving fiber (RF)
DC CRCH HR
The relative light power :
Huimin Cao. et al. (2007).
OFBDS with twin RF bundles
Simulation
19
CH CR DC HR
Huimin Cao. et al. (2007).
OFBDS with twin RF bundles
CI : inner circular RFCO : outer circular RF
DC – type has highest sensitivity
Simulation
19
CH CR DC HR
Huimin Cao. et al. (2007).
CI : inner circular RFCO : outer circular RF
OFBDS with twin RF bundles
DC – type has highest sensitivity
Experiment
20
Double circular (DC) - type
The root-mean-square (RMS) voltage
The relative RMS voltage
: current responsivity
: feedback resistance
: voltage gain: relative light power Huimin Cao. et al. (2007).
Results
21Huimin Cao. et al. (2007).
The theoretical curves vs the experimental results vs displacement
P1 : total received power
from RF-1 bundles
P2 : total received power
from RF-2 bundles: relative light power
Discussion :
22
The sensitivity of OFBDS
with single RF bundle
with twin RF bundles
The normalized sensitivity
Sensitivity
Huimin Cao. et al. (2007).
H : High
Z : ZeroL : Low
23
Discussion
24
Discussion
25
Discussion
26
Discussion
Application of OFBDS
27
Liquid level sensingThe sensing of surface roughness
Hang Zhou Yang. et al. (2014).
single RF bundle
twin RF bundles
No
rmal
ized
po
wer
(m
V)
single RF bundle
Conclusion
28
OFBDS containing one TF bundle and two RF bundles was created.
OFBDS containing one TF bundle and one RF bundle was still worked fine but it depends on reflectivity.
29
References
Cao, H., Chen, Y., Zhou, Z., & Zhang, G. (2007). Theoretical and experimental study on the optical fiber bundle displacement sensors. Sensors and Actuators A: Physical, 136(2), 580-587.
Yang, H. Z., Qiao, X. G., Luo, D., Lim, K. S., Chong, W., & Harun, S. W. (2014). A review of recent developed and applications of plastic fiber optic displacement sensors. Measurement, 48, 333-345.
Q&A
Numerical aperture (NA)
: Acceptance angle
https://www.pantechsolutions.net/blog/numerical-aperture-of-optical-fiber-cable/
https://slideplayer.com/slide/8979465/
CH CR DC HR
Huimin Cao. et al. (2007).
N. Sangeetha. et al. (2017).
Shot noise where : electron charge: equivalent noise bandwidth
Johnson noise where : Boltzmann constants
: temperature in K
Noise Equivalent Displacement (NED)
single receiving system
twin receiving system
: voltage gain: sensitivity of OFBDS
where
Resolution
Huimin Cao. et al. (2007).
Dynamic range (DR)
• Linear range (LR)• Noise equivalent displacement (NED)
Huimin Cao. et al. (2007).
Random (R)
Concentric (C)
Hemicircular (H)
Double circular (DC)
Concentric hemicircular (CH)
Concentric random (CR)
Hemicircular random (HR)
Transmitting fiber (TF)
Receiving fiber (RF)
Huimin Cao. et al. (2007).
The received power is
Huimin Cao. et al. (2007).
Huimin Cao. et al. (2007).
The distance from a fiber to the origin is
The distance between a and a is
1
R
r
c
r
c
g
Transmitting fiber (TF)
Receiving fiber (RF)
Random (R) - type
Optical fiber bundle displacement sensors (OFBDS)
Simulation
1R C HHuimin Cao. et al. (2007).
1
Integral model
Theoretical model : Fiber bundle model
m groups of different p
suppose
: distribution density of p
Huimin Cao. et al. (2007).
1
Integral model
Theoretical model : Fiber bundle model
1
Theoretical model : Fiber bundle model
Summation model
Integral model
Expanded model
Theoretical model : Fiber bundle model
: reflectivity of target surface
: light power emitted from TF
: modulation function
Summation model
The total received power is
1
???
Integral model
Theoretical model : Fiber bundle model
: reflectivity of target surface
: light power emitted from TF
: modulation function
Summation model
The total received power is
Integral model
1
1
Theoretical model : Fiber bundle model