Study On Orthogonal Polarization Dual-wavelength Laser Based On Nd³⁺ Doped MgO:LiNbO₃

Orthogonal polarization dual-wavelength lasers are widely used in high-precision laser ranging,laser medical treatment,spectral analysis and other fields,especially in the field of laser ranging,because of the accuracy can be improved effectively by its unique polarization,so that it has broad application prospects.In recent years,orthogonally polarized dual-wavelength laser output based on neodymium ion doped crystals has become a research hotspot gradually.Research on orthogonally polarized dual-wavelength lasers is mostly seen in dual-wavelength alternate output or synchronous output.However,There are relatively few researches on controlling the orthogonally polarized dual-wavelength output based on the crystals of Nd:MgO:LN.Therefore,this article combines the thermal effects of Nd:MgO:LN crystals with dual-wavelength studies.By designing resonators with different parameters,the feasibility of the adjustable orthogonal polarization dual-wavelength is verified.The theoretical basis and technical support is provided by Nd:MgO:LN crystal controllable orthogonal polarization dual-wavelength laser output.Firstly,the absorption and emission characteristics of Nd:MgO:LN crystal are analyzed based on the laser characteristics of Nd:MgO:LN matrix crystal.Combined with the laser oscillation energy level theory,the formation of 1084 nm and 1093 nm orthogonally polarized dual-wavelength laser output of Nd:MgO:LN crystal is studied.In terms of theory,the physical and chemical characteristics and optical properties of Nd:MgO:LN crystals and the energy level theory of Nd:MgO:LN crystals are analyzed.The relationships between the 1084 nm/1093 nm stimulated emission cross section and the crystal temperature rise are shown in this paper.The thermal effect of the Nd:MgO:LN crystal is simulated,and the temperature rise of the crystal under different pump powers is obtained,and the thermally induced orthogonal polarization double of the Nd:MgO:LN crystal is analyzed based on the fitted thermal focal length of the measured crystal.Based on those,structural parameters such as single-ended pumping and double-ended pumping resonant cavity length,cavity mirror curvature,and spot matching are optimized.In terms of experiment,two kinds of orthogonal polarization dual-wavelength output characteristic experiments based on the single-ended and double-ended pumping were carried out.By changing the structural parameters of the resonator,the stable operation of the orthogonal polarization dual-wavelength laser based on the Nd:MgO:LN crystal was realized.Under the condition of single-ended pumping,the output power of 3.47 W at 1093 nm,the output power of 2.71 W at 1084 nm and the output power 3 W at 1084 nm/1093 nm were obtained,respectively.Under the condition of double-ended pumping,the highest6.02 W 1093 nm laser and 3.02 W 1084 nm pure single-wavelength laser output and 4.58 W dual-wavelength laser output are obtained.The experimental measurement shows that the1084 nm and 1093 nm dual-wavelength belong to orthogonal polarization linearly polarized light,It is verified that the orthogonal polarization dual-wavelength output can be effectively adjusted by changing the cavity parameters...