本論文提出利用錯位熔接與蝕刻布拉格光纖光柵來製作雙參數光纖感測器，可同時感測外在環境溫度及折射率的變化。我們的元件製作方法簡單，只需光纖切割及錯位熔接，再利用蝕刻布拉格光纖光柵的方式縮小光纖直徑以提升元件對環境的靈敏度。光纖纖核的錯位使得元件一部分的纖核模態分光到纖殼形成纖殼模態，由於兩個模態對於環境參數有不同的感測靈敏度，因此我們可以藉由量測兩個模態各自的反射波長位移量來達到雙參數感測的目的。
我們對蝕刻前後的元件進行量測，並討論熔接錯位量及蝕刻對反射頻譜的影響。由實驗量測可以得到，在折射率量測範圍1.333到1.3723之間，蝕刻前之元件纖核模態與纖殼模態對折射率感測靈敏度分別為0 nm/RIU及0.51nm/RIU，而蝕刻後的感測靈敏度分別為0 nm/RIU及1.73nm/RIU，說明蝕刻元件能有效地提升纖殼模態的感測靈敏度。在應變量測方面，蝕刻前之元件纖核模態與纖殼模態應變感測靈敏度分別為0.6 pm/µԑ以及0.57 pm/µԑ，而蝕刻後的感測靈敏度分別為4.37 pm/µԑ以及3.67 pm/µԑ，其感測靈敏度皆明顯提高。此外，蝕刻後之元件纖核模態與纖殼模態對溫度感測靈敏度分別為10.7pm/⁰C 以及10.4pm/⁰C，與蝕刻前的結果相近。

We propose a bi-parameter sensor formed by splicing an etched fiber Bragg grating (FBG) with an offset for simultaneous sensing temperature and refractive index (RI). The fabrication method contains only fiber cutting and misaligned fusing, and we employ chemical etching to reduce the diameter of FBG for enhancing the sensing sensitivity. The misaligned splicing divides the core mode into the core mode and cladding mode. The two modes show different sensing sensitivities for environment variation, which can be used to realize bi-parameter sensing.
The reflection spectra of our device are investigated for different misalignments and etching diameters. Before etching, the RI sensitivities of core mode and cladding mode as the RI ranged from 1.333 to 1.3723 are 0nm/RIU and 0.51nm/RIU, respectively. The strain sensitivities of core mode and cladding mode from 0µԑ to 250µԑ are 0.6 pm/µԑ and 0.57 pm/µԑ, respectively. After etching, the RI sensitivities become 0 nm/RIU and 1.73nm/RIU, and the strain sensitivities are 4.37 pm/µԑ and 3.67 pm/µԑ. These results prove that the sensitivities are indeed increased after etching. Moreover, the temperature sensitivities of core mode and cladding mode remain 10.7pm/⁰C and 10.4pm/⁰C from 30⁰C to 90⁰C after etching.

學位論文審定書 i
致謝 ii
摘要 iii
Abstract iv
目錄 v
圖目錄 vii
表目錄 x
第一章 續論 1
1-1 光纖的發展 1
1-2 光纖光柵感測器 3
1-2.1長週期光纖光柵(Long-period fiber grating) 4
1-2.2布拉格光纖光柵(Fiber Bragg grating) 6
1-2.3週期漸變型光纖光柵(Chirped fiber Bragg grating) 9
1-2.4斜角布拉格光纖光柵(Tilted fiber Bragg grating) 11
1-3 研究動機 13
第二章 布拉格光纖光柵 14
2-1 布拉格定律 14
2-2 布拉格光纖光柵 16
第三章 錯位熔接與蝕刻布拉格光纖光柵雙參數感測器之製作 22
3-1 錯位熔接布拉格光纖光柵之製作 22
3-1.1元件設計 22
3-1.2元件製作 23
3-2 蝕刻錯位熔接之布拉格光纖光柵 26
3-2.1元件製作 26
3-2.2蝕刻製程特性 28
第四章 錯位熔接與蝕刻布拉格光纖光柵雙參數感測器之特性 30
4-1 實驗架設 30
4-2 不同熔接錯位量之反射頻譜 31
4-3 元件蝕刻之量測結果與討論 35
第五章 錯位熔接與蝕刻布拉格光纖光柵雙參數感測器之感測應用 37
5-1 元件蝕刻前之感測 37
5-1.1溫度感測特性 37
5-1.2折射率感測特性 41
5-1.3應變感測特性 44
5-2 元件蝕刻後之感測 48
5-2.1溫度感測特性 49
5-2.2折射率感測特性 52
5-2.3應變感測特性 55
5-2.4溫度與折射率之雙參數感測矩陣 58
第六章 結論 61
參考文獻 62

J. Hecht, “A short history of laser development,” Applied Optics, vol. 49, pp. 091002-1-091002-23, 2010.
K. C. Kao and G. A. Hockham, “Dielectric-fibre surface waveguides for optical frequencies,” Proceedings of the Institution of Electrical Engineers-London, vol. 113, pp. 1151-1158, 1966.
D. Gloge, “Weakly guiding fibers,” Applied Optics, vol. 10, pp. 2252-2258, 1971.
L. V. Nguyen, D. Hwang, S. Moon, D. S. Moon, and Y. Chung, “High temperature fiber sensor with high sensitivity based on core diameter mismatch,” Optics Express, vol. 16, pp. 11369-11375, 2008.
Y. P. Wang, L. Xiao, D. N. Wang, and W. Jin, “Highly sensitive long-period fiber-grating strain sensor with low temperature sensitivity,” Optics Letters, vol. 31, pp. 3414-3416, 2006.
Z. Tian, S. S. H. Yam, and H. P. Loock, “Single-mode fiber refractive index sensor based on core-offset attenuators,” IEEE Photonics Technology Letters, vol. 20, pp. 1387-1389, 2008.
Y. Gong, T. Zhao, Y. J. Rao, and Y. Wu, “All-fiber curvature sensor based on multimode interference,” IEEE Photonics Technology Letters, vol. 23, pp. 679-681, 2011.
H. Yan, D. Han, M. Li, and B. Lin, “Relative humidity sensor based on surface plasmon resonance of D-shaped fiber with polyvinyl alcohol embedding Au grating,” Journal of Nanophotonics, vol. 11, pp. 016008-1-016008-7, 2017.
S. Silva, L. Coelho, and O. Frazão, “An all-fiber Fabry-Pérot interferometer for pressure sensing in different gaseous environments,” Measurement, vol. 47, pp. 418-421, 2014.
Z. Li, C. Liao, J. Song, Y. Wang, F. Zhu, Y. Wang, and X. Dong, “Ultrasensitive magnetic field sensor based on an in-fiber Mach-Zehnder interferometer with a magnetic fluid component,” Photonics Research, vol. 4, pp. 197-201, 2016.
H. Yu, X. Yang, Z. Tong, Y. Cao, and A. Zhang, “Temperature-independent rotational angle sensor based on fiber Bragg grating,” IEEE Sensors Journal, vol. 11, pp. 1233-1235, 2011.
R. Slavík, J. Homola, J. Čtyroký, and E. Brynda, “Novel spectral fiber optic sensor based on surface plasmon resonance,” Sensors and Actuators B, vol. 74, pp. 106-111, 2001.
S. M. Melle, A. T. Alavie, S. Karr, T. Coroy, K. Liu, and R. M. Measures, “A Bragg grating-tuned fiber laser strain sensor system,” IEEE Photonics Technology Letters, vol. 5, pp. 263-266, 1993.
H. Y. Fu, H. Y. Tam, L. Y. Shao, X. Dong, P. K. A. Wai, C. Lu, and S. K. Khijwania, “Pressure sensor realized with polarization-maintaining photonic crystal fiber-based Sagnac interferometer,” Applied Optics, vol. 47, pp. 2835-2839, 2008.
S. J. Mihailov, “Fiber Bragg grating sensors for harsh environments,” Sensors, vol. 12, pp. 1898-1918, 2012.
K. O. Hill and G. Meltz, “Fiber Bragg grating technology fundamentals and overview,” Journal of Lightwave Technology, vol. 15, pp. 1263-1276, 1997.
H. J. Patrick, A. D. Kersey, and F. Bucholtz, “Analysis of the response of long period fiber gratings to external index of refraction,” Journal of Lightwave Technology, vol. 16, pp. 1606-1612, 1998.
A. M. Vengsarkar, P. J. Lemaire, J. B. Judkins, V. Bhatia, T. Erdogan, and J. E. Sipe, “Long-period fiber gratings as band-rejection filters,” Journal of Lightwave Technology, vol. 14, pp. 58-65, 1996.
B. Li, L. Jiang, S. Wang, H. L. Tsai, and H. Xiao, “Femtosecond laser fabrication of long period fiber gratings and applications in refractive index sensing,” Optics and Laser Technology, vol. 43, pp. 1420-1423, 2011.
W. J. Bock, J. Chen, P. Mikulic, and T. Eftimov, “A novel fiber-optic tapered long-period grating sensor for pressure monitoring,” IEEE Transactions on Instrumentation and Measurement, vol. 56, pp. 1176-1180, 2007.
H. Xuan, W. Jin, and M. Zhang, “C"O" _"2" laser induced long period gratings in optical microfibers,” Optics Express, vol. 17, pp. 21882-21890, 2009.
S. W. James and R. P. Tatam, “Optical fibre long-period grating sensors: characteristics and application,” Measurement Science and Technology, vol. 14, pp. R49-R61, 2003.
A. Othonos, “Fiber Bragg gratings,” Review of Scientific Instruments, vol. 68, pp. 4309-4341, 1997.
L. H. Kang, D. K. Kim, and J. H. Han, “Estimation of dynamic structural displacements using fiber Bragg grating strain sensors,” Journal of Sound and Vibration, vol. 305, pp. 534-542, 2007.
S. W. James, M. L. Dockney, and R. P. Tatam, “Simultaneous independent temperature and strain measurement using in-fibre Bragg grating sensors,” Electronics Letters, vol. 32, pp. 1133-1134, 1996.
M. Han, F. Guo, and Y. Lu, “Optical fiber refractometer based on cladding-mode Bragg grating,” Optics Letters, vol. 35, pp. 399-401, 2010.
S. Wu, G. Yan, C. Wang, Z. Lian, X. Chen, and S. He, “FBG incorporated side-open Fabry-Pérot cavity for simultaneous gas pressure and temperature measurements,” Journal of Lightwave Technology, vol. 34, pp. 3761-3767, 2016.
Q. Yao, H. Meng, W. Wang, H. Xue, R. Xiong, and B. Huang, “Simultaneous measurement of refractive index and temperature based on a core-offset Mach-Zehnder interferometer combined with a fiber Bragg grating,” Sensors and Actuators A, vol. 209, pp. 73-77, 2014.
Y. Okabe, R. Tsuji, and N. Takeda, “Application of chirped fiber Bragg grating sensors for identification of crack locations in composites,” Composites: Part A, vol. 35, pp. 59-65, 2004.
D. Srivastava, R. Bhatnagar, A. Kumar, and V. Parmar, “Intensity modulation using chirped fiber Bragg grating as an edge filter for temperature sensing,” Microwave and Optical Technology Letters, vol. 56, pp. 2913-2915, 2014.
Y. P. Miao, B. Liu, and Q. D. Zhao, “Refractive index sensor based on measuring the transmission power of tilted fiber Bragg grating,” Optical Fiber Technology, vol. 15, pp. 233-236, 2009.
W. L. Bragg, “The diffraction of short electromagnetic waves by a crystal,” Proceddings of the Cambridge Philosophical Society, vol. 17, pp. 43-57, 1913.
M. Weidemüller, A. Hemmerich, A. Görlitz, T. Esslinger, and T. W. Hänsch, “Bragg diffraction in an atomic lattice bound by light,” Physical Review Letters, vol. 75, pp. 4583-4586, 1995.
K. O. Hill, Y. Fujii, D. C. Johnson, and B. S. Kawasaki, “Photosensitivity in optical fiber waveguides: Application to reflection filter fabrication,” Applied Physics Letters, vol. 32, pp. 647-649, 1978.
V. Mizrahi and J. E. Sipe, “Optical properties of photosensitive fiber phase gratings,” Journal of Lightwave Technology, vol. 11, pp. 1513-1517, 1993.
M. Yamada and K. Sakuda, “Analysis of almost-periodic distributed feedback slab waveguides via a fundamental matrix approach,” Applied Optics, vol. 26, pp. 3474-3478, 1987.
S. Pawar, S. Kumbhaj, P. Sen, and P. K. Sen, “Fiber Bragg grating filter for optical communication: Applications and overview,” International Journal of Advanced Electrical and Electronics Engineering, vol. 2, pp. 51-58, 2013.
X. Wang, A. Jiang, and C. Madsen, “Chalcogenide As2S3 sidewall Bragg gratings integrated on LiNbO3 substrate,” Optics and Photonics Journal, vol. 3, pp. 78-87, 2013.
D. J. Monk, D. S. Soane, and R. T. Howe, “A review of the chemical reaction mechanism and kinetics for hydrofluoric acid etching of silicon dioxide for surface micromachining applications,” Thin Solid Films, vol. 232, pp. 1-12, 1993.
G. Meltz and W. W. Morey, “Bragg grating formation and germanosilicate fiber photosensitivity,” International Workshop on Photoinduced Self-Organization Effects in Optical Fiber, vol. 1516, pp. 185-199, 1991.
T. V. A. Tran, Y. G. Han, J. H. Lee, S. H. Kim, and S. B. Lee, “Effects of fiber cladding diameter on cladding-mode coupling in fiber Bragg gratings,” Japanese Journal of Applied Physics, vol. 44, pp. 1278-1281, 2005.
W. M. B. M. Yunus and A. B. A. Rahman, “Refractive index of solutions at high concentrations,” Applied Optics, vol. 27, pp. 3341-3343, 1988.
C. Y. Lin, L. A. Wang, and G. W. Chern, “Corrugated long-period fiber gratings as strain, torsion, and bending sensors,” Journal of Lightwave Technology, vol. 19, pp. 1159-1168, 2001.
A. D. Kersey, M. A. Davis, H. J. Patrick, M. LeBlanc, K. P. Koo, C. G. Askins, M. A. Putnam, and E. J. Friebele, “Fiber grating sensors,” Journal of Lightwave Technology, vol. 15, pp. 1442-1463, 1997.