Sb2Te3 mode-locked ultrafast fiber laser at 1.93 μm<xref rid="cpb_27_8_084214_fn1" ref-type="fn">*</xref><fn id="cpb_27_8_084214_fn1"><label>*</label>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).</fn>

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).

Wang Jintao^{1, 2}, Yin Jinde^{1, 2}, He Tingchao³, Yan Peiguang^{1, †}

(color online) (a) Optical spectrum with the bandwidth of 3.87 nm. (b) Radio frequency (RF) spectrum at fundamental frequency of 14.51 MHz with 10-Hz resolution. The inset was the RF spectrum of 1-GHz span. (c) Autocorrelation trace for output pulse with a pulse duration of 1.24 ps with sech² fit. The inset shows the autocorrelation trace with a large range of 50 ps. (d) Relationship between the pump power and output power. The inset is the oscilloscope trace of the pulse-train.