Research progress of Bi-doped silica-based fibers for wide-band amplifier and laser application in SIOM
M. Guo1, J. Tian12, X. Li13, F. Wang1, Y. Wang1, C. Yu1'3'4*, L. Hu134*
1- Advanced Laser and Optoelectronic Functional Materials Department, Special Glasses and Fibers Research Center, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China 2- School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China 3- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing
100049, China
4- Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
* sdycllcy@163. com, * hulili@siom.ac.cn
In order to meet the growing demand of communication capacity, bismuth-activated glass fibers with broadband near-infrared luminescence (1000-1800 nm) covering the second communication window are considered promising candidates for a new generation of wide-band amplifiers and tunable lasers. Significant progress has been made in the development of Bi-doped silica-based fibers (BDF) abroad. Nowadays, the Bi-doped fiber amplifiers and lasers have been systematically studied aboard, and thus to hatch series of products.
Since 2021, some breakthroughs of Bi-doped fiber amplifiers and lasers have been made in SIOM [1-5]. We achieved the optical amplification in the O, E, S and U band based on the homemade BDFs. Based on the highly phosphorous and bismuth co-doped silica fiber (BPDF), a maximum gain of 38.3 dB at 1330 nm was obtained in the double pass setup for a signal power of -30 dBm and pump one of 785 mW at 1240 nm. For the E+S-band amplification, a gain coefficient as high as 1.57 dB/m and a maximum gain of 39.3 dB were achieved using only 25 m lowly germanium and bismuth co-doped silica fiber (BGDF). For the highly germanium and bismuth co-doped silica-based fiber (Hi-BGDF), we proposed that germanium oxygen vacancy defects play a pivotal role in promoting the formation of the bismuth near-infrared active luminescence centers BAC-Ge [6]. According to the above mechanism, we built a U-band fiber amplifier based on the home-made Hi-BGDF. A maximum gain of 31.8 dB at 1750 nm was measured when the pump power was 936 mW at 1550 nm. More importantly, a gain coefficient as high as 0.48 dB/m at 1750 nm with a maximum gain above 23 dB was obtained based on another Hi-BGDF with higher absorption coefficient.
In addition, we achieved laser output based on above BDFs. Furthermore, a single-frequency fiber laser (SFFL) operating at 1440 nm based on BGDF has been obtained for the first time. A maximum slope efficiency of 16.4% and output power of 133 mW at 1313 nm were achieved with 96 m BPDF in a linear cavity structure. For the SFFL at 1440 nm, the maximum single-longitudinal-mode laser output power of about 6 mW was obtained with an OSNR of more than 75 dB. Based on the Hi-BGDF, the output power of 48 mW at 1720 nm was achieved with an OSNR of 60 dB in a linear cavity structure.
[1] M. Guo, J. Tian, F. Wang, et al, Amplification in E band based on highly phosphorus and bismuth co-doped silica fiber, Chinese Journal of Luminescence, vol.4, pp. 478-481, (2022).
[2] J. Tian, M. Guo, F. Wang, et al, High gain E-band amplification based on the low loss Bi/P co-doped silica fiber, Chinese optics Letters, vol.20, pp. 100602, (2022).
[3] J. Tian, M. Guo, F. Wang, et al, High gain optical amplification and lasing performance of the Bi/P co-doped silica fiber in the O-band, Chinese optics Letters, vol.21, pp. 050601, (2023).
[4] M. Guo, J. Tian, F. Wang, et al, E+S-band amplification based on the homemade germanium and bismuth co-doped silica fiber, Chinese Journal of lasers, vol. 50, pp. 0616002, (2023).
[5] M. Guo, J. Tian, F. Wang, et al, Domestic high germanium bismuth-doped silica-based fiber for high gain U-band amplification, Chinese Journal of lasers, vol. 50, pp. 2416006, (2023).
[6] X, Li, M, Guo, C, Shao, et al, Broadband L+ near-infrared luminescence in bismuth/germanium co-doped silica glass prepared by the solgel method, Journal of Materials Chemistry C, vol.11, pp. 16152-16158, (2023).