1Huazhong University of Science and Technology, Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information, Wuhan, China
2Optics Valley Laboratory, Wuhan, China
3Shenzhen Institute of Huazhong University of Science and Technology, Shenzhen, China
4Yangtze Optical Fiber and Cable Joint Stock Limited Company (YOFC), State Key Laboratory of Optical Fiber and Cable Manufacture Technology, Wuhan, China
Recently, transmitting diverse signals in different cores of a multicore fiber (MCF) has greatly improved the communication capacity of a single fiber. In such an MCF-based communication system, mux/demux devices with broad bandwidth are of great significance. In this work, we design and fabricate a 19-channel mux/demux device based on femtosecond laser direct writing. The fabricated mux/demux device possesses an average insertion loss of 0.88 dB and intercore crosstalk of no more than - 29.1 dB. Moreover, the fabricated mux/demux device features a broad bandwidth across the C+L band. Such a mux/demux device enables low-loss 19-core fiber (de)multiplexing over the whole C+L band, showing a convincing potential value in wavelength-space division multiplexing applications. In addition, a 19-core fiber fan-in/fan-out system is also established based on a pair of mux/demux devices in this work.