High-resolution compact spectrometer based on periodic tapered coreless fiber
Hongzhou Chen, Zhenyu Duan, Chunying Guan, Xixin Li, Shan Gao, Xiao Hu, Peng Ye, Jing Yang, Ping Li, Jinhui Shi, Libo Yuan
Abstract
This Letter proposes a method that balances miniaturization and high performance of fiber optic speckle spectrometers. The periodically tapered coreless fiber is used as the scattering element to excite more higher-order modes in the coreless fiber. As a result, a remarkable spectral resolution of 0.03 nm in the near-infrared spectrum can be achieved with a 5-cm-long fiber. Narrow linewidth and broadband spectra in the wavelength of 1540-1560 nm are reconstructed separately, demonstrating the excellent performance of the designed all-fiber spectrometer. The spectral resolution of our proposed spectrometer is comparable to that of a 2-m multimode fiber spectrometer and has a significant improvement in miniaturization.