Recent advances in Bi-doped silica-based optical fibers: A short review

Control of temperature dependent viscosity for manufacturing of Bi-doped active fiber

“…Recently, various Bi centers (e.g. Bi 5+ , Bi 3+ , Bi 2+ , Bi + , Bi 0 , Bi clusters and even nanocrystals) have been identified, and the usual metastable centers such as Bi + , Bi 0 and Bi clusters are regarded as the Bi active centers (BACs) which contribute to the NIR activity [14,26]. During the manufacturing of Bi-doped active fiber, these centers experienced the complicate and thermodynamic chain reactions of Bi metal particles ↔ Bi 3+ ↔ Bi + /Bi 0 ↔ Bi clusters and distinct centers are stabilized at various states [27].…”

“…For example, the first Bi-doped glass fiber was fabricated and found to show optical amplification at a wavelength of 1300 nm [9]. Later, Bi-doped phosphosilicate and germanosilicate glasses and fibers were invented and demonstrated to provide efficient optical amplification in a wide wavelength range of 1270 ∼ 1800 nm [10][11][12][13][14]. Importantly, the principal fiber amplifier device was also developed by the company of optical fiber cable and connectivity solutions [15][16][17].…”

Tunable ultra-broadband multi-band NIR emission in Bi-doped aluminogermanate glasses and fibers via controllable Al2O3 content for broadband amplifiers

“…[4][5][6][7] Great efforts have been carried out in Bi-doped silica fibers with various elements (Al, P, or Ge) for obtaining lasers and amplifiers operating in the 1150-1775 nm range, where the rare-earth ions are ineffective. 4,[8][9][10] These have led to Bi-doped glasses and fibers being evolved as interesting gain media for a new generation of tunable fiber lasers and broadband amplifiers to cope with the capacity requirements in optical fiber communication. 4 However, the permissible Bi doping concentration of Bi-doped silica fiber is very low (o0.02 at%) to demonstrate lasers and amplifiers, which leads to its unsatisfactory gain performance and longer device length.…”

“…4 However, the permissible Bi doping concentration of Bi-doped silica fiber is very low (o0.02 at%) to demonstrate lasers and amplifiers, which leads to its unsatisfactory gain performance and longer device length. 8 Consequently, Bi-doped multicomponent glasses have been developed for the preparation of novel gain fibers due to their low melting temperature, high Bi doping concentration, and flexible chemical composition. [11][12][13] So far, Bi NIR luminescence has been found in different multi-component glass systems, ranging from silicate, germanate, phosphate, and borate.…”

“…This leads to the multivalent states of Bi ions (such as +1, +2, +3, and +5) and the uncertainty of Bi NIR active centers (Bi + (B1100 nm), Bi 0 (1250 nm), and complexes formed by oxygen defects and low-valent Bi ions (B920 and B1500 nm)). 4,8 Thus, Bi ions in multi-component glasses exhibit glass component-dependent absorption and emission properties. Nevertheless, modifying the glass network structure by component manipulation has also become an effective method to explore the Bi NIR emission behaviors (e.g., peak wavelength, bandwidth, and emission intensity).…”