TY - JOUR
T1 - Dual Mach-Zehnder Interferometer Based on Side-Hole Fiber for High-Sensitivity Refractive Index Sensing
AU - Hu, Jie
AU - Shao, Liyang
AU - Gu, Guoqiang
AU - Zhang, Xuming
AU - Liu, Yanjun
AU - Song, Xuefeng
AU - Song, Zhangqi
AU - Feng, Jiansong
AU - Buczynski, Ryszard
AU - Smietana, Mateusz
AU - Wang, Taihong
AU - Lang, Tingting
PY - 2019/12
Y1 - 2019/12
N2 - A unique type of refractive index (RI) sensor is proposed using a dual Mach-Zehnder interferometer (MZI) structure based on side-hole fibers (SHFs). The MZI structure contains two single-mode fibers (SMFs), two coreless fiber (CLF) sections and an SHF section, which are spliced together in the order of SMF-CLF-SHF-CLF-SMF. The SMFs and the CLFs enable light lead in/out and beam splitting/combining, respectively. As a special feature of the structure, one hole of SHF is exposed for liquid filling and to form two MZIs as well. Three types of sensors are fabricated, namely S1, S2 and S3. Numerical simulation and experimental studies have been conducted to characterize the sensing performance. The RI sensitivity of the S1 using the ∼550 μm long SHF section reaches 14,000 nm/RIU. When a shorter SHF section is used in S2, the detectable RI range is broadened due to larger FSR. When the closed hole of SHF in S3 is filled with liquid to introduce the Vernier effect, the sensitivity can be further enhanced to over 44,000 nm/RIU (i.e., Refractive Index Unit), which corresponds to the detection limit at the level of 1.0 × 10-5 RIU. This sensor design is original and easy to package, which gives it potential for label-free biochemical analyses.
AB - A unique type of refractive index (RI) sensor is proposed using a dual Mach-Zehnder interferometer (MZI) structure based on side-hole fibers (SHFs). The MZI structure contains two single-mode fibers (SMFs), two coreless fiber (CLF) sections and an SHF section, which are spliced together in the order of SMF-CLF-SHF-CLF-SMF. The SMFs and the CLFs enable light lead in/out and beam splitting/combining, respectively. As a special feature of the structure, one hole of SHF is exposed for liquid filling and to form two MZIs as well. Three types of sensors are fabricated, namely S1, S2 and S3. Numerical simulation and experimental studies have been conducted to characterize the sensing performance. The RI sensitivity of the S1 using the ∼550 μm long SHF section reaches 14,000 nm/RIU. When a shorter SHF section is used in S2, the detectable RI range is broadened due to larger FSR. When the closed hole of SHF in S3 is filled with liquid to introduce the Vernier effect, the sensitivity can be further enhanced to over 44,000 nm/RIU (i.e., Refractive Index Unit), which corresponds to the detection limit at the level of 1.0 × 10-5 RIU. This sensor design is original and easy to package, which gives it potential for label-free biochemical analyses.
KW - Mach-Zehnder interferometer
KW - Optical fiber sensor
KW - refractive index sensing
KW - side-hole fiber
KW - Vernier effect.
UR - http://www.scopus.com/inward/record.url?scp=85077206790&partnerID=8YFLogxK
U2 - 10.1109/JPHOT.2019.2948087
DO - 10.1109/JPHOT.2019.2948087
M3 - Journal article
AN - SCOPUS:85077206790
SN - 1943-0655
VL - 11
JO - IEEE Photonics Journal
JF - IEEE Photonics Journal
IS - 6
M1 - 8873618
ER -