We report on the first application of a topological insulator based on antimony telluride (Sb2Te3) as a saturable absorber (SA) in a bulk microchip laser. The transmission-type SA consisted of a thin film of Sb2Te3 (thickness: 3 nm) deposited on a glass substrate by pulsed magnetron sputtering. The saturable absorption of the Sb2Te3 film was confirmed for ns-long pulses. The microchip laser was based on a Tm:GdVO4 crystal diode-pumped at ∼802 nm. In the continuous-wave regime, this laser generated 3.54 W at 1905-1921 nm with a slope efficiency η of 37%. The Q-switched laser generated a maximum average output power of 0.70 W at 1913 nm. The pulse energy and duration were 3.5 μJ and 223 ns, respectively, at a repetition rate of 200 kHz. The Sb2Te3 SAs are promising for passively Q-switched waveguide lasers at ∼2 μm.
In this paper we demonstrate a preliminary work done on employing antimony telluride (Sb2Te3) topological insulator as a saturable absorber for Yb-doped fiber lasers. The material was deposited onto a side-polished fiber by means of a pulsed magnetron sputtering technique. Fabricated absorber was implemented in an all-normal dispersion cavity and allowed for self-starting dissipative soliton generation. The laser emitted stable pulse train at a repetition rate of 17.07 MHz with 4.25 nm broad output spectrum centered around 1039.4 nm. Average output power amounted to 0.54 mW with 32 pJ pulse energy.
We demonstrate the usage of a saturable absorber material - antimony telluride (Sb2Te3) for efficient mode-locking of a Thulium-doped fiber laser. The Sb2Te3 layers were obtained by mechanical exfoliation and transferred onto the fiber ferrule. The all-fiber laser was capable of generating optical solitons with the full width at half-maximum of 4.5 nm centered at 1945 nm, with 39.5 MHz repetition rate and more than 60 dB signal to noise ratio. The pulse energy of the generated 890 fs pulses was at the level of 30 pJ. Our experiment showed that Sb2Te3 saturable absorbers are suitable for the operation in 2 μm bandwidth.