Square-Wave Pulse Passively Mode-Locked Thulium-Doped Fiber Laser With Adjustable Pulse Duration and Amplitude

• Main Authors: Yijuan Jiang, Simin Liu, Zuxing Zhang
• Format: Article
• Language: English
• Published: IEEE 2021-01-01
• Series: IEEE Photonics Journal
• Subjects: Square-wave pulse; noise-like pulse; thulium-doped fiber laser; mode-locked laser
• Online Access: https://ieeexplore.ieee.org/document/9436002/

A passively mode-locked thulium-doped fiber laser with square-wave pulse generation has been demonstrated using a figure-of-eight configuration with two gain mediums respectively located in the left and right loops. In this laser, mode-locking is achieved based on equivalent saturation absorption of a nonlinear amplifying loop mirror (NALM). The pulse amplitude and width of the square-wave pulse can be continuously extended through controlling pump power of gain mediums in the left and right loops. Moreover, the pulse dynamics and autocorrelation trace reveal the obtained square-wave pulse is a new kind of noise-like pulse, i.e., noise-like square-wave pulse, with capability of supporting higher pulse energy. This find enriches laser pulse dynamics and has important potential applications in laser detection, sensing and other fields.