Cluster Control for Construction of Bismuth‐Doped Glass Fiber with Broadband Optical Response

Abstract Bismuth(Bi)‐doped optical fibers are widely used in various aspects such as fiber lasers and amplifiers. Despite extensive research efforts to explore high‐gain Bi‐doped fibers, the pursuit of Bi‐doped fibers with emission over an extremely wide wavelength range remains unfulfilled. Here, the strategy of cluster control via regulating glass structure is proposed. It is applied to construct Bi‐doped photonic glass with ultra‐broadband near‐infrared (NIR) emission and a full width at half maximum (FWHM) of 343 nm. The strategy is further combined with the modified chemical vapor deposition (MCVD) technique with solution doping. The fiber exhibits ultra‐broadband amplified spontaneous emission (ASE) covering the entire fiber communication band (1260–1625 nm). Finally, the fiber exhibits higher optical gain and bandwidth compared with the fiber without cluster control. This device can be utilized to potentially enhance the capacity of telecommunication systems.