Broadband Optical Amplification of PbS Quantum‐Dot‐Doped Glass Fibers

The rapid development of global telecommunication, cloud computing, big data, consumer electronics create increasing demands to expand the capacity and rate of data transmission for next generation broadband optical communication. It raises a great challenge for current rare‐earth ions doped fiber amplifiers due to the narrow emission bandwidth of rare‐earth ions. In this context, broadband near‐infrared (NIR) emitter based optical amplifiers are in urgent demand. Here, broadband optical amplification in S + C + L bands is achieved for the first time in PbS quantum dot (QD)‐doped low‐melting‐point glass fiber. With the pump of a 976 nm laser, the on‐off gain of PbS QD‐doped fiber (PQDF) ranges from 1.4 to 8.7 dB in 1500–1630 nm, while that of PbS QD‐doped glass ranges from 6.9 to 8.4 dB in 1530–1630 nm. Both QD‐doped glass and optical fiber show tunable luminescence covering the entire optical communication windows (O + E + S + C + L + U). The much higher quantum yield of PbS QDs in glass than that of colloidal QDs, the ultra‐broad and controllable emission bands and bandwidth make PbS QDs doped glass and fiber promising for applications in next generation broadband optical fiber amplifiers and tunable fiber lasers.