REDUCED MODE SAPPHIRE FIBER AND DISTRIBUTED ......2017/03/22  · • Simple, cost effective,...

REDUCED MODE SAPPHIRE FIBER ANDDISTRIBUTED SENSING SYSTEM

DE-FE0012274

REDUCED MODE SAPPHIRE FIBER ANDDISTRIBUTED SENSING SYSTEM

DE-FE0012274

1

2017 CROSSCUTTINGResearch Project Review Omni William Penn HotelPittsburgh, PAMarch 22, 2017

Gary Pickrell, Anbo Wang, Daniel HomaVirginia Tech Center for Photonics TechnologyBlacksburg, VA 24061pickrell@vt.edu, awang@vt.edu, dan24@vt.eduhttp://photonics.ece.vt.edu/

OverviewOverview

• Motivation, Objectives, and Technical Challenges

• Research Approach and Technology• LMV Sapphire Fiber Design and Fabrication

• Distributed Temperature Sensing System

• Milestones and Schedule

• Impact and Achievements

• Next Steps

2

MotivationMotivation

• Eliminate barriers to the seamless integration of fiber optic sensing technologies in power plants

• Improve the operating efficiencies and safety of power plants via the real time and distributed sensing of temperature

3

Project Objectives Project Objectives

4

• Goal: Develop a Raman scattering distributed temperature sensing system based on a low modal volume (LMV) sapphire fiber sensor.

• Objective: Design, fabricate and characterize a sapphire fiber that limits the number of guided modes.

• Objective: Develop a prototype, fully-distributed sensing system and evaluate its performance in a laboratory test environment for operation at temperatures over 1000ºC.

• Benefit: The proposed sapphire fibers and sensors will allow for the seamless integration of mature fiber optic sensing technologies in new power plant control systems.

Technical ChallengesTechnical Challenges• Performance of single crystal sapphire fibers

• Large “core” diameters• High numerical aperture (NA)• High loss• Weak Raman signal in sapphire fiber

• High operating temperatures• Thermal radiation generated by the sapphire fiber• Thermal radiation coupled into the fiber end

• Achievable spatial resolution• Pulse width• Modal dispersion

5

TECHNOLOGY & APPROACHTECHNOLOGY & APPROACH

6

Research ApproachResearch Approach• Design and fabricate a single crystal sapphire fiber

with a modal volume optimized for sensor applications• Wet acid etching at elevated temperatures• “Bundled” photonic crystal sapphire fiber design• Sapphire fiber growth via LHPG

• Design and construct a Raman scattering distributed temperature sensing system• Interrogation at 532 nm • Design and component optimization• Performance testing

7

RESEARCH PROGRESS:LMV SAPPHIRE FIBER DESIGN AND FABRICATION

RESEARCH PROGRESS:LMV SAPPHIRE FIBER DESIGN AND FABRICATION

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• Sulfuric/phosphoric acid solutions• Studied and optimized concentrations

• Elevated temperatures (>200°C)• Determined etch rates• Determined activation energies• Studied a-plane vs. c-plane

• Extended lengths (~ 1m)• Improved surface quality

• Eliminated surface deposits• Simple, cost effective, scalable• Potential new applications

• Gas sensing, inclined tip sensing

LMV Sapphire Fiber FabricationFabrication via Wet Acid Etching LMV Sapphire Fiber FabricationFabrication via Wet Acid Etching

9

10

Sample Top Diameter (µm)

Bottom Diameter (µm)

A 82.0 73.1B 80.9 73.4C 79.6 74.4

Average 80.8 73.6Standard Deviation 1.2 0.7

LMV Sapphire Fiber FabricationEquipment and TechniquesLMV Sapphire Fiber FabricationEquipment and Techniques

Custom Etching SystemExcellent Temperature Control

Temperature and Etching Uniformity

11

LMV Sapphire Fiber FabricationUnderstanding and ControlLMV Sapphire Fiber FabricationUnderstanding and Control

Optimization of Etching Solution Etch Rates

12

60µm

LMV Sapphire Fiber FabricationCharacterization of Surface QualityLMV Sapphire Fiber FabricationCharacterization of Surface Quality

d = 11µm

Optical Microscopy(fiber diameter, contamination,

polarization states, non-uniformities)

Scanning Electron Microscopy (SEM)Energy-dispersive X-ray spectroscopy (EDAX)

(fiber diameter, contamination, composition/elemental analysis, defects, non-

uniformities)

• Three different wavelengths (532nm, 782.9nm, 982.9nm)• Focused into connector using direct free-space coupling

• Overfilled using objective lens with NA=0.66• Sample mounted on 3-axis stage• CCD camera beam profiler mounted on 3-axis stage• Polished fiber tip (100 nm lapping film)

LMV Sapphire Fiber TestingModal Volume MeasurementLMV Sapphire Fiber TestingModal Volume Measurement

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• Far-field intensity patterns capture• Prior to etching• Post etching and polishing

• Modal interference and superposition yields a “speckled” appearance

• Reduction in diameter and modal volume • Number of power peaks (speckles) decreases • Relative diameter of individual speckles increases• Modal interference and superposition due a

decrease in the number of supported modes

• Qualitative analysis of modal volume • Low order mode profiles are visible

LMV Sapphire Fiber TestingFar Field Analysis MethodLMV Sapphire Fiber TestingFar Field Analysis Method

Etching

“As-received” sapphire fiber

LMV sapphire fiber

Etching

Single mode sapphire fiber

14

15

LMV Sapphire Fiber TestingFar Field Analysis of RDSFLMV Sapphire Fiber TestingFar Field Analysis of RDSF

The trend in modal volume reduction with a reduction in fiber diameter and increase wavelength agrees with theoretical predictions

• Vary angle of waveguide tip with stationary photodetector (TIA standard)• Requires both ends of fiber to be connected• Requires decent fiber length (>1/3m)

• Vary input NA and measure output power• Assumes all intensity effects are NA-

dependent• Beam diameter differential

• Overfill fiber (all modes are excited)• Measure beam width twice with known

distance between• Vergence angle calculated from beam width

differential• Requires consistent beam projection to be

accurate (single mode)

LMV Sapphire Fiber TestingNA Characterization TechniquesLMV Sapphire Fiber TestingNA Characterization Techniques

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• The measured (“effective”) NA can deviate significantly from the theoretically calculated value • Non-ideal geometry (i.e. non-

circular cross section)• Small core diameter• Inefficient coupling, surface

scattering, angled end faces

LMV Sapphire Fiber TestingTheoretical vs. Effective NALMV Sapphire Fiber TestingTheoretical vs. Effective NA

• Beam width differential method• CCD camera beam profiler

(Thorlabs BC106-VIS)

Laser Heated Pedestal GrowthBasic ComponentsLaser Heated Pedestal GrowthBasic Components

• Beam Steering Optics• Imaging System• HeNe Alignment Laser• Polarizer-Attenuator-Analyzer• Gold Coated Copper Mirrors• Beam Expander

• Growth Chamber Optics• Aluminum Optics• In-house design and polishing• Reflaxicon, Scraper Mirror, Spherical Mirror

• Mechanical Drawing System• Synchronized Linear Stages

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Laser Heated Pedestal GrowthAutomatic Diameter Control SystemLaser Heated Pedestal GrowthAutomatic Diameter Control System

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Diameter variations ~1.7% were readily achieved

• For the first time, a submicron single crystal sapphire fiber for the propagation of lower order modes was fabricated via wet-acid etching

• Few mode operation was demonstrated, for the first-time, in a single crystal sapphire fiber

• Reduction of the “effective” NA and modal volume was verified via an array of characterization techniques and test parameters

• A fully operational LHPG system was designed and constructed in-house for the fabrication of unique sapphire fiber structures

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LMV Sapphire FiberSummary of ResultsLMV Sapphire FiberSummary of Results

RESEARCH PROGRESS:DISTRIBUTED TEMPERATURE SENSING SYSTEM

RESEARCH PROGRESS:DISTRIBUTED TEMPERATURE SENSING SYSTEM

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Operating Wavelength SelectionBlackbody RadiationOperating Wavelength SelectionBlackbody Radiation

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• The Raman intensity of the Anti-Stokes and Stokes components is proportional to its differential cross section given by (M. Hobel, Applied Optics, 1995)

• According to Planck’s law, the radiation can be calculated as followed (M. Planck, P. Blakiston’s Son & Co, 1914)

200 400 600 800 1000 1200 14000

2

4

6

8

10

12

14

16

Temperature(oC)

Nor

mal

ized

Inte

nsity

(u.a

)

Raman temperature sensitivity vs. temperature 418 cm-1

Anti-StokesStokes

0 500 1000 1500 2000 2500 30000

0.01

0.02

0.03

0.04

0.05

0.06

Wavelength (nm)

Spec

tral r

adia

nce

(kW

.sr-1

.m-2

.nm

-1)

Blackbody radiation in sapphire

500 oC800 oC1100 oC1400 oC

4

1 1

exp 1

AS

x AS

B

dd hc

K T x

4

1 1

1 exp

S

x S

B

dd hc

K T x

2

5 1

2 1( )B

hck T

hcB Te

• Experimental setup for Raman scattering detection.• Temperature distribution along the sapphire fiber.

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0 0.2 0.4 0.6

200

400

600

800

1000

Length (m)Te

mpe

ratu

re (o C)

1033oC858oC680oC497oC300oC

B. Liu et al, Optics Letters, 2015

Scattering in Sapphire Fiber Experimental Set-UpScattering in Sapphire Fiber Experimental Set-Up

510 520 530 540 550 560

0

500

1000

1500

2000

2500

3000

3500

4000

4500

Cou

nts

(a.u

.)

Wavelength (nm)

Sapphire Raman signal with thermal background removed

25 oC300 oC497 oC680 oC858 oC1033 oC

0 200 400 600 800 10000.5

1

1.5

2

2.5

I(T)/I

(300

o C)

Max temperature ( oC)

A 751A 418S 418S 751

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Spectrum Peak Intensity

B. Liu, Optics Letters, 2015

Scattering in Sapphire Fiber Temperature DependenceScattering in Sapphire Fiber Temperature Dependence

0 200 400 600 800 1000-15

-10

-5

0

5

10

15

20

25

Freq

uenc

y ch

ange

(cm

-1)

Max temperature (oC)

Temperature dependence of sapphire Raman position

A 751A 418S 418S 751

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0 200 400 600 800 100030

40

50

60

70

80

90

100

Freq

uenc

y (c

m-1

)

Max temperature (oC)

Temperature dependence of sapphire Raman width

A 418S 418S 751

Peak Frequency

B. Liu, Optics Letters, 2015

Scattering in Sapphire Fiber Temperature DependenceScattering in Sapphire Fiber Temperature Dependence

Peak Width

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0 500 1000 1500 2000 2500 3000 3500 4000 45000

200

400

600

800

1000

1200

1400

Tem

pera

ture

(o C)

Time (minutes)

Temperature profile

B. Liu et al, Optics Letters, 2016

Raman DTS System Design Experimental Set-UpRaman DTS System Design Experimental Set-Up

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Nor

mal

ized

Ant

iSto

kes (

a.u.

)

B. Liu et al, Optics Letters, 2016

Raman DTS System Performance1 meter Sapphire Fiber Raman DTS System Performance1 meter Sapphire Fiber

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0 200 400 600 800 1000 1200 14000

5

10

15

20

25

30

Temperature (oC)

Nor

mal

ized

Inte

nsity

(a.u

.)

Stokes & AntiStokes VS Temperature

StokesAntiStokes

0 0.05 0.1 0.15 0.20

200

400

600

800

1000

1200

1400

Raman Ratio

Tem

pera

ture

(o C)

3.44664.5177

3.1515

3.5239

3.5828

3.1952

3.063

4.1128

4.6922

4.103

3.4676

3.7131

3.9338

4.54334.2505

3.1918

3.5211

4.0517

4.2584

3.5247

3.8062

2.8226

3.5343

4.9308

3.1315

3.1366

Temperature-riseTemperature-fall Curve fitting

Standard deviation

B. Liu et al, Optics Letters, 2016

Standard Deviation: 3.7ºC (3.0ºC)

Raman DTS System Performance1 meter Sapphire Fiber Raman DTS System Performance1 meter Sapphire Fiber

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0 500 1000 1500 2000 2500 3000 3500 4000 45000

200

400

600

800

1000

1200

1400

Dem

odul

ated

tem

pera

ture

(o C)

Time (minutes)

Demodulated signal at heating center

Raman DTSThermal couple

0 0.2 0.4 0.6 0.8 10

200

400

600

800

1000

1200

1400

Tem

pera

ture

(o C

)

Distance (m)

Temperature profile along the fiber

30 oC100 oC200 oC300 oC400 oC500 oC600 oC700 oC800 oC900 oC1000 oC1100 oC1200 oC

Raman DTS System Performance1 meter Sapphire Fiber Raman DTS System Performance1 meter Sapphire Fiber

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-2 -1 0 1 2 3-0.2

0

0.2

0.4

0.6

0.8

1

1.2

Distance (m)

Nor

mal

ized

Sto

kes

(a.u

.)

Stokes VS Temperature

200 oC400 oC600 oC800 oC1000 oC1200 oC

-2 -1 0 1 2 3-1

0

1

2

3

4

5

Distance (m)N

orm

aliz

ed A

ntiS

toke

s (a

.u.)

AntiStokes VS Temperature

200 oC400 oC600 oC800 oC1000 oC1200 oC

Raman DTS System Performance2 meter Sapphire Fiber Raman DTS System Performance2 meter Sapphire Fiber

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-0.5 0 0.5 1 1.5 2 2.5 3 3.5 4-0.2

0

0.2

0.4

0.6

0.8

1

Distance (m)

Nor

mal

ized

Ant

iSto

kes

(a.u

.)

AntiStokes VS Temperature

224 oC433 oC632 oC826 oC1020 oC1216 oC

Joint reflection

-0.5 0 0.5 1 1.5 2 2.5 3 3.5 4-0.2

0

0.2

0.4

0.6

0.8

1

Distance (m)

Nor

mal

ized

Sto

kes

(a.u

.)

Stokes VS Temperature

224 oC433 oC632 oC826 oC1020 oC1216 oC

Raman DTS System Performance3 meter Sapphire Fiber Raman DTS System Performance3 meter Sapphire Fiber

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0 0.5 1 1.5 2 2.5 30

0.1

0.2

0.3

0.4

0.5

0.6

X: 2.768Y: 0.3104

Position (m)

Volta

ge (m

V)

Raman Anti-Stokes signal

X: 2.464Y: 0.01163

X: 2.721Y: 0.28

X: 2.557Y: 0.04118

Raman DTS System PerformanceSpatial ResolutionRaman DTS System PerformanceSpatial Resolution

• Sensing length: 3 meters• Temperature: 1400ºC• Spatial resolution: 16.4 cm

– Determined via 10% to 90% response distance

• Raman fully-distributed ultra-high temperature sensing technique, a first-of-its-kind technology, was successfully demonstrated.

• A temperature standard deviation of 3.0ºC (0.2% of full scale) was demonstrated in a 1 meter sapphire fiber.

• A maximum operating temperature of 1400ºC was demonstrated (upper limit has yet to be determined)

• A spatial resolution <20 cm was achieved with a fiber sensing length of 3 m.

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Raman DTS System Summary of ResultsRaman DTS System Summary of Results

MILESTONES AND SCHEDULEMILESTONES AND SCHEDULE

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Project MilestonesProject Milestones

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M. # Title/DescriptionPlanned

Completion Date

Actual Completion

Date

1 Project Management Plan 5/15/2014 5/8/2014

2 Modeling of LMV Sapphire Fiber & Sensing System 12/31/2014 12/31/2014

3 Demonstration of LMV Sapphire Fabrication 6/30/2015 6/30/2015

4 Demonstration of Sensing System 12/31/2015 12/31/2015

5 Prototype System Test Results 6/29/2016 6/29/2016

6 Final Report 12/31/2016 85%

• LMV sapphire fiber • Demonstrated design feasibility• Developed fabrication processes• Demonstrated fiber performance

• Fully-distributed temperature sensing system• Demonstrated design feasibility• Characterized Raman scattering

response in sapphire fibers• Demonstrated system performance

in fused silica optical fibers• Demonstrated prototype system in

single crystal sapphire fibers

Milestone Success CriteriaMilestone Success Criteria

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• LMV sapphire fiber • Demonstrated significantly reduce modal volume (<< 50%)

• Few mode and single mode operation• Minimum bend radius << 4 mm

• Bend radius < 100 µm

• Fully-distributed temperature sensing system• Sapphire sensing lengths of 1, 2, and 3 meters • Spatial resolutions < 17 cm• Operating temperature ~ 1400ºC

ID Title Description Result M.S.Planned

CompletionActual

Completion

1. 50% modal volume reduction 1. >> 50% modal volume reduction2. Sensing length of 3 m 2. Sensing length of 3 m3. Resolution of < 20 cm 3. Resolution < 17 cm1. 40% reduction in modal volume 1. > 50 % modal volume reduction2. Attenuation < 6 dB/m @ 355 nm 2. Attenuation < 8 dB/m @ 532 nm3. Minimum bend radius < 25 mm 3. Minimum bend radius < 4 mm1. Sensing length of 2 m 1. Sensing length of 3 m2. Resolution < 20 cm 2. Resolution < 10 cm

Distributed Temperature Sensing: Distributed Temperature Sensing: 1. Sensing length of 3m 1. Sensing length of 3 m2. Resolution < 20 cm 2. Resolution < 17 cm

System Modeling M2 12/31/2014

SC2 LMV Sapphire Fiber M3 6/30/2015

SC1

SC3 Distributed Sensing System 12/31/2015M4

SC4 Prototype Test Results M5 6/29/2016

12/31/2014

6/30/2015

12/31/2015

6/29/2016

Review Panel RecommendationsReview Panel Recommendations

• All Recommendations have been addressed• On schedule and budget

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RPR # Title/Description Planned Completion Date

Actual Completion Date

Verification Method

Comments (progress toward achieving milestone,

explanation of deviation from plan, etc.)

R1 Material Characterization of Pre‐ and Post‐ Etched Sapphire Fibers 9/30/2016 9/30/2016 DOE Approval Completed

R2 "Back of the Envelope" Calculations to Predict Fiber and System Performance 3/30/2016 3/30/2016 DOE Approval Completed

R3 Identify a "Back‐up Approach"/Alternative Strategies 12/30/2016 12/30/2016 DOE Approval Completed

R4 Engage Crystal Growth Experts for LHPG  9/30/2016 9/30/2016 DOE Approval Completed

R5 Evaluate Consistencies between Theoretical Anlyses and Experimentation/Manufacturability 12/30/2016 12/30/2016 DOE Approval Completed

Project ScheduleProject Schedule

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Ext.Y4

Task # Task Name Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q11 Project Management and Planning 1/1/2014 5/15/2014 1/1/2014 5/8/20142 Determine Technical Requirements 1/1/2014 5/15/2014 1/1/2014 5/8/2014

M1* MILESTONE 1*

3Optical Modeling of LMV Sapphire and Distributed Sensor System

2/3/2014 12/30/2014 2/3/2014 12/30/2014

3.1 LMV Sapphire Fiber Modeling 2/3/2014 12/30/2014 2/3/2014 12/30/2014

3.2Sapphire Fiber Based High Temperature Distributed Sensing Modeling

4/1/2014 12/30/2014 4/1/2014 12/30/2014

M2 MILESTONE 2

4Demonstrate Feasibility of LMV Sapphire and Distributed Sensing System

4/2/2014 12/31/2015 2/1/2014 12/31/2015

4.1 LMV Sapphire Fiber Fabrication 4/1/2014 6/26/2015 2/1/2014 6/30/2015M3 MILESTONE 3

4.2Distributed Sensing System Building and Demonstrating with Silica Fiber

5/1/2014 12/29/2015 2/1/2014 12/31/2015

M4 MILESTONE 4

5Develop LMV Sapphire Fiber Temperature Sensing System

9/1/2015 6/30/2016 7/1/2015 6/16/2016

5.1 Construct Prototype LMV Sapphire Fiber 9/1/2015 1/4/2016 9/1/2015 5/1/2016

5.2

Demonstrate Distributed High Temperature Sensing with LMV Sapphire Fiber

1/14/2016 5/18/2016 10/1/2015 6/16/2016

5.3 Perform Sensor Calibration and Verification5/19/2016 6/28/2016 6/1/2016 6/29/2016

M5 MILESTONE 5

6Construct & Evaluate Refined Prototype Sensing System

6/30/2016 11/30/2016 7/16/2016

6.1Fabricate Refined Version of LMV Sapphire Fiber

6/30/2016 8/22/2016 7/20/2016

6.2Construct Refined Version of LMV Sapphire Fiber Distributed Sensing System

6/29/2016 9/15/2016 7/20/2016

6.3 Test Sensor and Evaluate Performance 9/16/2016 10/28/2016 11/20/20167 Prepare and Submit Final Report 11/11/2016 11/11/2016 10/20/2016

M6 MILESTONE 6

Completed

Comments

Completed

BUDGET PERIOD 1 BUDGET PERIOD 2Project Year 1 Project Year 2 Project Year 3 Planned

Start Date

KEY PROJECT DATES

Completed

Completed                          

On Schedule                        No Cost Extension Granted

5/15/2014 (4/1/2014)* 4/28/2014*

12/31/2014

6/29/2015

12/31/2015

6/29/2016

12/31/2016

Planned End Date

Actual Start Date

Actual End Date

Completed

GANT CHART

12/31/2014

6/29/2015

12/31/2015

√

√

√

√

√

IMPACT, ACHIEVEMENTS, AND NEXT STEPSIMPACT, ACHIEVEMENTS, AND NEXT STEPS

39

Research ImpactResearch Impact• Technical Achievements

• Fabrication of sub-micron single crystal sapphire fiber • Observation of Raman Stokes and Anti-Stokes peaks in sapphire fiber • Measurement of fiber attenuation in the time domain in sapphire fiber • Distributed Raman temperature measurements in sapphire fiber • Demonstrated few to single mode operation in sapphire fiber

• Student Support• Full Support: Cary Hill (Ph.D, ‘16). Bo Liu (Ph.D., ’17),

Yujie Cheng (Ph.D., ‘17)• Partial: Adam Floyd (Ph.D., ‘17), Jiaji He, (Ph.D., TBD),

Hanna Heyl (Ph.D., TBD), Shuo Yang, (Ph.D., ‘19), Amiya Behera (Ph.D, ‘17) Chennan Hu (Ph.D., TBD), Sunny Chang (M.S., ‘16), Elizabeth Bonnell (M.E., ‘16)

• Faculty Training & Development• Zhihao Yu (Post-doc)• Daniel Homa (Research Scientist)• Haifeng Xuan (Research Associate)• Chenyuan Hu (Post-doc)

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Research ProductsResearch Products• Peer Reviewed Publications

• Hill, Cary, Daniel Homa, Bo Liu, Zhihao Yu, Anbo Wang, and Gary Pickrell. Submicron Diameter Single Crystal Sapphire Optical Fiber, Materials Letters 138, no. 0 (2015): 71-73.

• Bo Liu, Zhihao Yu, Zhipeng Tian, Daniel Homa, Cary Hill, Anbo Wang, and Gary Pickrell. Temperature dependence of sapphire fiber Raman scattering, Opt Lett. 2015; 40(9):2041-4.

• Cheng, Yujie, Cary Hill, Bo Liu, Zhihao Yu, Haifeng Xuan, Daniel Homa, Anbo Wang and Gary Pickrell. Modal Reduction in Single Crystal Sapphire Optical Fiber, Optical Engineering 54, no. 10 (2015): 107103.

• Yujie Cheng, Cary Hill, Bo Liu, Zhihao Yu, Haifeng Xuan, Daniel Homa, Anbo Wang, and Gary Pickrell. Design and analysis of large-core single-mode windmill single crystal sapphire optical fiber, Optical Engineering, 55 (2016) 066101-066101.

• Liu, Bo, Zhihao Yu, Daniel Homa, Yujie Cheng, Gary Pickrell, and Anbo Wang. Sapphire-Fiber-based Distributed High Temperature Sensing System, Optics Letters, 41(18), 4405-4408.

• Hill, Cary, Dan Homa, Zhihao Yu, Yujie Cheng, Bo Liu, Anbo Wang and Gary Pickrell. Single Crystal Sapphire Optical Fiber, Applied Sciences (submitted for publication).

• Intellectual Property• U.S. Patent Application No. 62/057,291; Processing Technique for the Fabrication of Sub-

micron Diameter Sapphire Optical Fiber, G. Pickrell, D. Homa, W. Hill, filed Sept. 30, 2014.• U.S. Patent Application No. 62/264,659. Distributed Temperature Sensing System Using

Optical Sapphire Waveguide, A. Wang, G. Pickrell, B. Liu, Z. Yu., Dec. 2015.

41

Project PerformanceProject Performance

42

• All Project Milestones Met On Time and On Budget• All Success Criteria Met On Time and On Budget• “First of Its Kind” Technologies

– Fabrication of sub-micron single crystal sapphire fiber – Fabrication and demonstration of single mode sapphire fiber– Observation of Raman Stokes and Anti-Stokes peaks in sapphire fiber – Measurement of fiber attenuation in the time domain in sapphire fiber– Distributed Raman temperature measurements in sapphire fiber

• Dissemination of Findings– 5 peer reviewed publications, 1 submitted, 2 planned– 2 provisional patents filed

• Graduate Student Support (11)• Faculty Training and Development (4)

Next StepsNext Steps

43

• Compose manuscripts and submit for publication• Generate and submit Final Report• DTS system integration with LMV sapphire fiber• Process development and optimization of LHPG system• Submit continuation application • Evaluate additional research opportunities for fiber and

sensing technologies

AcknowledgementsAcknowledgementsVirginia Tech Center for Photonics Technology (CPT)Gary PickrellAnbo WangZhihao YuBo LiuCary HillDi HuAdam FloydYujie ChengSunny ChangElizabeth BonnellHann HeylZhiting TianHaifeng XuanRobert BlackwellAmy Hill, Jiaji He, Shuo Yang, Amiya Behera, Chennan Hu, Cindy Purdue, Chenyuan Hu, Nevada Davis

44

Department of EnergyNational Energy Technology Laboratory Project Manager: Jessica MullenSydni CredleSusan Maley*

*Now with Electric Power Research Institute

THANK YOU FOR YOUR TIMETHANK YOU FOR YOUR TIME

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