Fig. 1. Schematic of fabrication process of 7×1 chalcogenide glass fiber combiner

Fig. 2. Experimental setup for measuring of chalcogenide fiber combiner. (a) Port transmission efficiency; (b) output spot

Fig. 3. Transmission spectra,linear refractive indices of As-S glasses and the calculated NA of the fiber.(a) Transmission spectra; (b) linear refractive indices and the calculated NA of the fiber

Fig. 4. Attenuation of fabricated As-S fiber, the inset shows the cross section of the fiber

Fig. 5. Design diagram of the fiber combiner. (a) Schematic cross section of 7×1 fiber combiner formed by tightly packed fibers; (b) schematic diagram of light transmission in tapped fiber

Fig. 6. The relationship between critical L and Δn for different taper ratio R

Fig. 7. The relationship between P_clad/P_total and Δn for different taper ratio R

Fig. 8. Images of the output end of fabricated fiber combiner. (a) R=3; (b) R=4

Fig. 9. The captured light spots at the output end of the fiber combiner with R=3 and R=4. (a) R=3,3 μm; (b) R=3,4.6 μm; (c) R=4,3 μm; (d) R=4,4.6 μm

Fig. 10. Beam quality M². (a) The beam quality M² of the laser after passing through a single multimode fiber; (b) the beam quality M² of the laser after passing through a single tapered fiber in the combiner