| 1064nm/1319 nm dual-wavelength laser has a wide range of applications.Especially in the field of sodium beacons,the 589 nm laser generated by the 1064 nm / 1319 nm sum frequency can effectively detect the high-altitude atmospheric sodium layer,but at the same time it needs to have a high output power.Laser amplification technology is one of the good ways to improve the output of laser.In summary,LD pumped Nd:YAG1064nm/1319 nm dual-wavelength laser/amplifier is studied theoretically and experimentally.The main contents are as follows :In theory,firstly,the design of dual-wavelength lasers is mainly divided into two ideas : common cavity and beam combination.The beam combination dual-wavelength laser is essentially a combination of two single-wavelength lasers,and the theoretical research has been relatively complete.Therefore,the analysis of common cavity dualwavelength laser is the key work of the laser part in this thesis.According to the energy level structure and transition process of Nd:YAG crystal,the delay trigger time of double Q-switch are introduced,and the rate equations of LD pumped Nd:YAG 1064nm/1319 nm dual wavelength Q-switched laser are established.The waveform of laser pulse output is obtained by simulation,and the influence of delay time on dual-wavelength laser pulse output is analyzed.Secondly,the theoretical model of dual-wavelength laser amplifier is established.The variation of dual-wavelength laser output power with crystal length is obtained by simulation,and then the output characteristics of dual-wavelength laser amplifier under different pump light and different seed light ratios are analyzed.Finally,for the common-cavity dual-wavelength laser,the stable region diagram of the resonant cavity in a certain thermal focal length range is obtained by simulation,and then the selection range of the resonant cavity length of the common-cavity dual-wavelength laser is obtained.For the combined-beam dual-wavelength laser,based on the equivalent confocal cavity theory,the cavity structure and the choice of cavity mirror curvature of the combined-beam dual-wavelength laser are confirmed by simulation.For the combined beam dualwavelength laser,based on the equivalent confocal cavity theory,the cavity structure and cavity mirror curvature of the dual-wavelength laser are determined by simulation.In the experimental design of dual-wavelength amplifier,according to the thin lens transformation theory of Gaussian beam,the focal length and spatial position of the seed light focusing mirror are determined by simulation,which provides design parameters for the experimental study of dual-wavelength amplifier.In the experiment,the experimental platform was built,and the Nd:YAG crystal with doping concentration of 1at.% was selected for the experimental study of dual-wavelength laser and dual-wavelength amplifier.The first is the experimental study of common-cavity dual-wavelength laser.In the continuous output mode of the dual-wavelength laser,When the pump power is 16.5 W,the maximum dual-wavelength laser output power is 2.25 W and 0.673 W,respectively.In the Q-switched output mode of the dual-wavelength laser,when the pump laser changes from 10.30 W to 13.95 W,in order to achieve simultaneous output of the dual-wavelength laser,the Q-switch delay trigger time should change between1200 ns and 1460 ns.When the delay trigger time is 1310 ns,the dual-wavelength laser has the same average power output at the same time.In this case,the average power of dualwavelength laser is 255 m W and 258 m W,and the pulse width is 63.33 ns and 196.5ns,respectively.In the combined-beam dual-wavelength laser,the output power of 1064 nm laser is 0.1W-2W adjustable,and the output power of 1319 nm laser is 0.1W-2W adjustable.Finally,in the dual-wavelength laser amplification experiment,according to the different design of seed source,the amplification of dual-wavelength seed laser with different ratio is studied.When the seed light ratio is 7:10,the output power of1064nm/1319 nm dual-wavelength laser amplifier is 1.093 W and 1.105 W respectively,which basically realizes the 1:1 output of the amplified laser. |
PDF Full Text Request