Sb2Te3 mode-locked ultrafast fiber laser at 1.93 μm**Project supported by the National Natural Science Foundation of China (Grant Nos. 61775146, 11704260, 61405126, and 61605122), the Shenzhen Science and Technology Project (Grant Nos. JCYJ20160427105041864, JSGG20160429114438287, KQJSCX20160226194031, JCYJ20160422103744090, and JCY20150324141711695), and the Natural Science Foundation of Guangdong Province, China (Grant Nos. 2016A030310049, 2016A030310059, and 2017A030310402).

Abstract

Ultrafast pulse generation was demonstrated in thulium doped fiber laser mode locked by magnetron sputtering deposited Sb2Te3 with the modulation depth, non-saturable loss, and saturable intensity of 38%, 31.2%, and 3.3 MW/cm2, respectively. Stable soliton pulses emitting at 1930.07 nm were obtained with pulse duration of 1.24 ps, a 3-dB spectral bandwidth of 3.87 nm, an average output power of 130 mW, and signal-to-noise ratio (SNR) of 84 dB. To our knowledge, this is the first demonstration of Sb2Te3-based SA in fiber lasers at 2-μm regime.