[en] We report a tunable single-longitudinal-mode laser based on a wedged Nd:YVO₄ gain medium and a YVO₄ wave-plate. By taking advantage of the natural birefringence of YVO₄ and adopting different cutting methods, a wedged Nd:YVO₄ crystal acts as an ideal polarizer by the alignment sensitivity of the optical resonator, and a YVO₄ crystal is used as a wave-plate by adjusting the temperature. A theoretical analysis of the single- longitudinal-mode operation of such a laser configuration is presented. The wavelength can be continuously tuned by the temperature at approximately 0.025 nm/°C, and the temperature tuning ranges of single-longitudinal-mode operation at pump powers of 1 W and 2 W are from 12 °C to 30 °C and from 11 °C to 26 °C, respectively. The maximum single-longitudinal-mode output power with linear polarization is 762 mW at a pump power of 2.2 W with a slope efficiency of 40%.

[en] Highlights: • A Poly(deep eutectic solvent)@Biomass was prepared as a novel separation medium. • The Poly(DES)@BioMs effectively removed trace DNA toxic compounds. • The removal process was based on multi-physical interactions. • The removal process was investigated using equilibrium/kinetic models. • The removal mechanisms were explored using molecular simulations. DNA toxic compounds (DNA-T-Cs), even in trace amounts, seriously threaten human health and must be completely eliminated. However, the currently used separation media face great challenges in removing trace DNA-T-Cs. Based on the functional advantages of deep eutectic solvents (DESs) and the natural features of biomass (BioM), a series of Poly(DES)@BioMs functioning as adsorbents were prepared for the removal of aromatic/hetero-atomic DNA-T-Cs at the ppm level. After optimisation of experimental conditions, the removal efficiency for DNA-T-Cs ranged from 92.4% to 96.0% with an initial concentration of 20.0 ppm, a temperature of 30 °C, duration of 30 min, and pH of 7.0. The removal processes between the DNA-T-Cs and Poly(DES)@BioMs are well described in the Temkin equilibrium and second-order kinetic adsorption models, and the desorption processes are well shown in the Korsmeryer–Peppas equilibrium and zero-order kinetic models. Molecular simulations revealed that the removal interactions include hydrogen bonding, π–π stacking, and hydrophobic/hydrophilic effects. The removal efficiency for the DNA-T-Cs at 8.0 ppm in industrial sewage ranged from 69.7% to 102%, while the removal efficiency for the DNA-T-Cs standing alone at 20.0 ppm in a methyl violet drug solution was 95.4%, confirming that the Poly(DES)@BioMs effectively removed trace DNA-T-Cs in field samples.