Multiple soliton mode-locking operations of a Holmium-doped fiber laser based on nonlinear polarization rotation

• Published in: Optics and laser technology 2023-06, Vol.161, p.109218, Article 109218
• Main Authors: Hu, Ping, Mao, Jiajia, Zhou, Xue, Feng, Tianli, Nie, Hongkun, Wang, Ruihua, Zhang, Baitao, Li, Tao, He, Jingliang, Yang, Kejian
• Format: Article
• Language: English
• Subjects: Bunched solitons; Harmonic mode-locking; Ho-doped fiber laser; Multiple pulse
• ISSN: 0030-3992; 1879-2545
• DOI: 10.1016/j.optlastec.2023.109218

•Multiple soliton mode-locking operation in the > 2000 nm region is realized.•Bunched solitons operation is firstly realized in the Ho-doped fiber laser.•The 965 fs, 139.19 MHz HML pulse is firstly realized in a Ho-doped fiber laser. Multiple soliton mode-locking operations are realized in a Holmium-doped (Ho-doped) fiber laser based on nonlinear polarization rotation (NPR) technique. The fundamental mode-locking (FML) operation with a repetition rate of 19.91 MHz and a pulse duration of 974 fs is realized at 2056.1 nm. Bunched solitons operation with up to 7 soliton pulses is firstly implemented in the Ho-doped fiber laser by increasing the pump power. The Ho-doped fiber laser can also evolve into the harmonic mode-locking (HML) operation at ∼ 2056 nm by finely adjusting the intra-cavity parameters. The pulse duration is 965 fs at the highest repetition rate of 139.19 MHz, which is believed to be the first report on the femtosecond HML operation in the Ho-doped fiber lasers.