A nano-lateral heterojunction of selenium-coated tellurium for infrared-band soliton fiber lasers

In this work, ultrafast fiber lasers based on 2D selenium-coated tellurium nanosheets in the infrared band are reported. 2D selenium-coated tellurium as a mode locker is shown with broadband saturable absorption and is capable of supporting ultra-stable pulse trains with several hundred-femtosecond pulse widths in the laser cavity. In particular, the as-fabricated 2D selenium-coated tellurium based fiber laser source operating in the communication band (1.5 μm) exhibits the vector pulse property, which supports the study of the vector soliton in ultrafast fiber lasers. The pulse duration of vector solitons is as short as 800 fs. The 2D selenium-coated tellurium is also available for a mode locked fiber laser operating at 1 μm. The laser oscillator has a pulse duration of several picoseconds and the pulse train is ultra-stable after an amplification to 100 mW, which is a promising seed source in the chirped-pulse amplification system in the future.