D.P. Sudas1, E.A. Savelyev2, K.M. Golant3

1,2 Fryazino branch of Kotelnikov IRE of RAS (Fryazino, Russia)

1,3 Kotelnikov IRE of RAS (Moscow, Russia)

Problem formulating. Bismuth telluride Bi2Te3 has proven to be an effective saturable absorber for the manufacture of passive Q-switches for fiber lasers. This material belongs to the class of topological insulators with surface states that are resistant to environmental conditions, in particular to temperature. Using Bi2Te3 in combination with an amorphous medium in the form of a polymer, one can expect a strong dependence of the optical properties of the resulting mixture on the ambient temperature due to a change in the refractive index of the polymer.

Goal. To study the effect of lowering the temperature of a passive Q-switch in the ring of a fiber laser resonator on the characteristics of the laser's output pulsed radiation.

Result. It has been found that lowering the temperature of saturable absorbers in the form of Bi2Te3 nanopowder-polymer composition makes it possible to increase the pulse repetition rate up to 30% at the same pump power. An erbium fiber laser showed the presence of a maximum in the dependence of the pulse repetition rate on temperature. During the cooling process, the wavelength of the laser radiation peak changes from 1560 to 1530 nm.

Practical meaning. This work can serve as a basis for the development of design concepts and the creation of new types of fiber lasers tunable in terms of the generation wavelength.

Sudas D.P., Savelyev E.A., Golant K.M. Cooling of passive Q-switches based on silicone-coated bismuth telluride in erbium fiber lasers. Nonlinear World. 2022. V. 20. № 2. P. 38-42. DOI: https://doi.org/10.18127/j20700970-202202-08 (In Russian)

1. Bogusławski J. et al. Exploiting nonlinear properties of pure and Sn-doped Bi2Te2Se for passive Q-switching of all-polarization maintaining ytterbium- and erbium-doped fiber lasers. Scientific Reports. 2017. V. 7.
2. Gao L. et al. Q-switched mode-locked erbium-doped fiber laser based on topological insulator Bi2Se3 deposited fiber taper. Applied Optics. 2014. V. 53. P. 5117-5122.
3. Tabib-Azar M. et al. Fiber optic electric field sensors using polymer-dispersed liquid crystal coatings and evanescent field interactions. Sensors and Actuators: B. 2000. V. 84. P. 134–139.
4. Lee H. et al. Polarization insensitive graphene saturable absorbers using etched fiber for highly stable ultrafast fiber lasers. OPTICS EXPRESS. 2015. V. 23. P. 22116.