Arrayed waveguide gratings (AWGs) in ZBLAN fibers for switchable dual-wavelength fiber lasers in the O- and S-band regions

In this work, the potential of arrayed waveguide gratings (AWGs) in ZrF4-BaF2-LaF3-AlF3-NaF (ZBLAN) fibers to produce a dual-wavelength fiber laser (DWFL) is presented, covering the O- and S- communication bands. These DWFLs are rarely reported, and this is the first demonstration in these bands using AWGs and ZBLAN fibers with dopants such as praseodymium and thulium. The O-band DWFL was achieved in a praseodymium-doped fluoride fiber laser (PDFFL), and the S-band DWFL was obtained in thulium-doped fluoride fiber lasers (TDFFLs). The dual wavelength with a wavelength spacing of 2.7 nm was generated at operating wavelengths of 1307.4 and 1310.1 nm in the O-band. Meanwhile, the S-band DWFL was generated at operating wavelengths of 1503.6 and 1505.9 nm, with a wavelength spacing of 2.3 nm. The two DWFLs were switched by changing AWG channels within the PDFFL and TDFFL cavities. The O-band and S-band DWFLs were switchable at wavelength spacings of 2.7–22.8 nm and 2.3–20.8 nm, respectively. These DWFLs in communication bands provide opportunities for possible applications in dense wavelength division multiplexing high-speed optical networks.