Near 0.5 dB gain per unit length in O-band based on a Bi/P co-doped silica fiber via atomic layer deposition

In this work, bismuth doped fiber (BDF) and bismuth/phosphosilicate co-doped fiber (BPDF) were fabricated by atomic layer deposition (ALD) combined with the modified chemical vapor deposition (MCVD). The spectral characteristics are studied experimentally and the BPDF has good excitation effect covering the O band. A diode pumped BPDF amplifier with the gain over 20 dB from 1298-1348 nm (50 nm) has been demonstrated. The maximum gain of 30 dB was measured at 1320 nm with a gain coefficient of around 0.5 dB/m. Furthermore, we constructed different local structures through simulation and found that compared with the BDF, BPDF has a stronger excited state and a greater significance in O-band. This is mainly because phosphorus (P) doping changes the associated electron distribution and forms the bismuth-phosphorus active center. The fiber has a high gain coefficient, which is of great significance for the industrialization of O-band fiber amplifier.

Automated summary

Bismuth doped fiber (BDF) and bismuth/phosphosilicate co-doped fiber (BPDF) were fabricated using atomic layer deposition (ALD) combined with modified chemical vapor deposition (MCVD). The spectral characteristics of the fibers were experimentally studied, showing that BPDF has good excitation effect in the O band. A diode pumped BPDF amplifier with a gain over 20 dB from 1298-1348 nm (50 nm) was demonstrated, with a maximum gain of 30 dB observed at 1320 nm and a gain coefficient of around 0.5 dB/m. Simulation results also showed that BPDF has a stronger excited state and greater significance in the O-band compared to BDF, mainly due to the formation of bismuth-phosphorus active centers through phosphorus (P) doping. The high gain coefficient of the fiber is of great importance for the industrialization of O-band fiber amplifiers.