Tapered fiber optic refractive index sensor using speckle pattern imaging

ARI F., Şerbetçi H., NAVRUZ İ.

OPTICAL FIBER TECHNOLOGY, cilt.79, 2023 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 79
  • Basım Tarihi: 2023
  • Doi Numarası: 10.1016/j.yofte.2023.103366
  • Dergi Adı: OPTICAL FIBER TECHNOLOGY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Compendex, INSPEC
  • Anahtar Kelimeler: Optical fiber sensor, Refractive index, Speckle pattern, Taper geometry effect, Tapered optical fiber
  • Ankara Üniversitesi Adresli: Evet

Özet

In this study, a low-cost and compact refractive index (RI) sensor based on speckle pattern imaging has been proposed and demonstrated numerically and experimentally. We have proven that speckle pattern images recorded with a CCD camera placed at the end of the tapered optical fiber (TOF) are highly sensitive to the RI of the medium to be measured. The effects of the waist diameter and length of the tapered region, which is the sensing part of the fiber, on sensitivity were investigated using the beam propagation method (BPM). It has been seen that the numerical results have compatible with the experimental results. Tapered fiber sensor was fabricated by electric arc discharge technique using step index multimode fiber (SI-MMF) with core and cladding diameters of 105 and 125 & mu;m. The sensor sensitivity increases as the waist diameter decreases and the waist length increases. The sensor, which waist diameter is reduced to 10 & mu;m, is sensitive to RI changes of the order of 10-4. It has been clearly seen that the proposed sensor based on speckle pattern imaging is highly sensitive to RI change.