Covering 1280-1495 nm (215 nm) wideband high-gain bismuth-doped fiber amplifier with only 1240 nm pumping

In this study, two bismuth-doped fibers were fabricated by atomic layer deposition (ALD) combined with modified chemical vapor deposition (MCVD) technology. For a dual-pump amplification configuration, 1240 and 1310 nm pumping the BDF simultaneously, when the 1240 nm pump power changes, it has little impact on the gain. The 1310 nm pump wavelength overlaps with the emission range of bismuth active centers associated with phosphorus (BACs-P), potentially suppressing its excitation. The experiment reveals that the emission range of BACs associated with silicon (BACs-Si) overlaps the absorption range of BACs-P, indicating that BACs likely exist for their reabsorption properties. Furthermore, enhancing the reabsorption properties can increase the luminescent intensity of BACs-Si in the 1420 nm region with only a 1240 nm pump. The gain of peaks at 1340 and 1420 nm exceeds 31.5 dB at a −23 dBm input signal. Notably, the gain within the 1280–1495 nm range exceeded 15 dB, achieving a bandwidth of 215 nm. This holds significant promise for applications in artificial intelligence, autonomous driving, and other fields with high-capacity communication demands.