Zhaogang Nie

Zhaogang Nie


Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 October 2023 in Micromachines
Verified
Journal Article
Open access
PDF file
LZLiqiang Zhang
Liqiang Zhang
KZKexin Zhu
Kexin Zhu
YYYicun Yao
Yicun Yao
XTXiuying Tian
Xiuying Tian
HXHailong Xu
Hailong Xu
ZNZhaogang Nie
Zhaogang Nie
Tunable fiber lasers have the advantages of good beam quality, high integration, and adjustable output wavelength, and they are widely used in fields such as optical fiber communication and optical fiber sensing. The fiber filter is one of the key components of tunable fiber lasers. Among the various filters currently used, multimode interference filters have the advantages of simple structure, convenient implementation, flexible tuning methods, and convenient spectral range design. The structures of multimode interference filters based on multimode fibers, no-core fibers, multi-core fibers, tapered fibers, and other special fibers are introduced in this paper. The working principles and tuning methods are analyzed and the research progress of tunable fiber lasers based on these filters is summarized. Finally, the development trend of tunable fiber lasers based on multimode interference filters is discussed. The rapid development and applications of multimode interference filters can help improve the performance of continuous and pulse lasers as well as promote the practicality of tunable fiber lasers.

23 May 2023 in Photonics
Verified
Journal Article
Open access
PDF file
燕张燕青 张
燕青 张
HMHaili Ma
Haili Ma
YYYicun Yao
Yicun Yao
MWMinghong Wang
Minghong Wang
LZLiqiang Zhang
Liqiang Zhang
CBChenglin Bai
Chenglin Bai
Multi-core fibers have been widely used for vector-bending sensing due to their off-axis distributed cores. In contrast to vector-bending sensors based on Bragg gratings, fiber Fabry–Perot (F–P) interferometers are more advantageous due to their ease of fabrication and potential for introducing the Vernier effect to further improve sensitivity. We propose and experimentally demonstrate a cascaded Fabry–Perot (F–P) cavity vector bending sensor. From the experimental results, the sensor has a strong bending dependence with a maximum sensitivity of 123.12 pm/m−1, and the curvature magnitude and direction can be reconstructed from the tilted wavelength shift of the asymmetric fiber-core F–P cavities.

16 October 2023 in Photonics
Verified
Journal Article
Open access
PDF file
XTXiuying Tian
Xiuying Tian
LZLiqiang Zhang
Liqiang Zhang
YYYicun Yao
Yicun Yao
HXHailong Xu
Hailong Xu
KZKexin Zhu
Kexin Zhu
ZNZhaogang Nie
Zhaogang Nie
An interference filter is designed by cascading two Mach-Zehnder interferometers (MZIs), which is then utilized in the construction of a wavelength interval adjustable dual-wavelength Erbium-doped fiber laser (EDFL). Each MZI consists of two 3 dB optical couplers (OCs) connected in series. The input light is split into two arms at the first OC and recombined at the second OC. The first MZI (MZI 1) has a smaller free spectral range (FSR) and is used for selecting the output wavelength of the laser. The second MZI (MZI 2) has a larger FSR and forms an envelope structure on the comb-like spectrum of MZI 1. By adjusting the optical path difference between the two arms of MZI 2, the FSR of the envelope can be changed, thereby altering the interval of the output wavelengths. The implemented filter is inserted into the EDFL to achieve stable dual-wavelength output. By stretching one arm of MZI 2, the interval of the dual-wavelength can be adjusted from 4.64 to 13.94 nm, with the side-mode suppression ratio of over 44 dB for all wavelengths.