Samples of the magneto-active material—Tb³⁺:Y₂O₃ ceramics with Tb³⁺ ion concentrations of 10%, 20%, 30%, and 100% (Tb₂O₃)—were prepared and studied. The wavelength dependence of Verdet constant in the 380 nm–1750 nm range was approximated for all investigated ceramic samples and was predicted for a pure Tb₂O₃ material. Tb₂O₃ ceramics demonstrates a more than three times higher Verdet constant in comparison with terbium gallium garnet crystal or ceramics. The linear dependence of the Verdet constant on Tb³⁺ ion concentration in the Tb³⁺:Y₂O₃ ceramics was demonstrated. The obtained data will be useful for fabricating magneto-optical elements of Faraday devices based on Tb³⁺:Y₂O₃ with arbitrary Tb³⁺ ion concentration operating at room temperature in the wavelength range of 380 nm–1750 nm.

The method of self-propagating high-temperature synthesis of submicron powders with subsequent vacuum sintering was used to produce a series of optical ceramics based on dysprosium oxide $({\mathrm{Dy}}_x{\mathrm{Y}}_{0.95-x}{\mathrm{La}}_{0.05}{)}_2{\mathrm{O}}_3$, where $x=0.7$, 0.85, and 0.9. The influence of ceramics composition on optical transmission of the obtained samples was investigated. The studied materials had several transparency windows in the visible 500–730 nm, near-IR 1900–2300 nm, and mid-IR 3500–7500 nm ranges. The dependence of the Verdet constant on wavelength in the 400–1940 nm range was measured for each ceramics composition, and analytical approximations were obtained. When Y and La dopants were used, the Verdet constant depended linearly on the concentration of ${\mathrm{Dy}}^{3+}$ ions, and its value in the visible wavelength range was about twice that of the analogous value for a terbium gallium garnet crystal. The high transmission and relatively high Verdet constant make the produced materials highly promising for fabricating Faraday devices for ${\mathrm{Tm}}^{3+}$ and ${\mathrm{Ho}}^{3+}$ lasers and for lasers emitting in the visible spectrum.

Simultaneous dual-wavelength laser oscillation of Tm:YLF at 1.9 and 2.3 μm were successfully realized. The three-mirror cavity was exploited to study dual-wavelength laser performance, which is formed by a shared input mirror and two independent output couplers for the two laser wavelengths. Under an absorbed pump power of 15.2 W, the maximum CW output powers of 5.49 W around 1908 nm and 1.12 W around 05 nm were simultaneously obtained, corresponding to a total optical-to-optical conversion efficiency of 43.5%. A Cr2+:ZnSe was further used to passively Q-switch the dual-wavelength laser, generating pulses with pulse widths of 554 ns at 1.9 μm and 4 μs at 2.3 μm. To the best of our knowledge, this is the first report on the dual-wavelength laser operation of Tm3+-single-doped solid-state laser at 1.9 and 2.3 μm. The higher optical conversion efficiency, smaller wavelength competition effect and simultaneous dual-wavelength output make this Tm-doped solid-state laser have potential application in real-time medical detection and treatment.