Investigation On Yb:YAG/Cr⁴⁺:YAG/YAG All-solid-state Dual-wavelength Lasers

With the rapid development of lasers,lasers with a single wavelength can't meet a variety of applications requirements.With regard to many important applications,such as terahertz waves,different absorption radar?DIAL?,laser display,blood detection,and spectral analysis,we need a laser emission dual-or multi-wavelength simultaneously.Compared with traditional dual-wavelength lasers,all solid state dual-wavelength lasers have a higher reliability and stability,and it has become a research focus.Based on research background of all solid state dual-wavelength based on Yb³⁺-doped crystal,a composite crystal was selected as a laser medium to investigate all solid state dual-wavelength lasers based on Yb:YAG crystal,combining proper nonlinear crystal and Raman crystal.The main contents of this thesis are as follows:1.The passively Q-switched dual-wavelength laser at 515 nm and 524.5 nm was firstly demonstrated by using Yb:YAG/Cr⁴⁺:YAG/YAG composite crystal and the LBO crystal.We investigated the output performance of dual-wavelength green laser,such as the average output power,the pulses,the output spectral and beam quality and etc.The possibility of dual-wavelength visible lasers for terahertz?THz?generation was discussed.2.The passively Q-switched dual-wavelength Raman laser at 1135 nm and 1157.5 nm was realized by using Yb:YAG/Cr⁴⁺:YAG/YAG composite crystal and the YVO₄ Raman crystal.The performances of dual-wavelength Raman laser were investigated,including the average output power,pulses,the output spectra and beam quality and etc.3.Based on the study of dual-wavelength Raman laser at 1135 nm and 1157.5 nm,a passively Q-switched yellow at 578.5 nm was obtained by employing a KTP crystal,and the performance of 578.5 nm laser was also investigated.This work provides a promising approach for the generation of 578 nm yellow laser.