Design Of A New Pulsed Solid State Laser Based On Niobium Carbide Aluminum

The pulse laser of 2μm waveband range is located in the window band of the atmosphere and the absorption peak of water molecules,which has played an irreplaceable role in atmospheric environment gas monitoring,the national military,medical treatment and other fields.The 2μm solid-state pulsed laser has the advantages of excellent compactness,long fluorescence life,high stability,high output beam quality and high coherence.In this paper,the output characteristics of passively Q-switched and passively mode-locking Tm:YLF laser based on the saturable absorber of aluminum niobium carbide were analyzed in detail.The main research contents were as followsFirst,the material structure of Nb₂Al C is an atomically thin layered material,that has attracted more and more attention in optoelectronics due to its excellent properties toward optical and physical,including a fast optical switching capability and high optical transparency,high elastic and excellent thermally conductivity.In this paper,the saturable absorber films of Nb₂Al C were prepared by ultrasonic thermal solution method and spin coating method,and Raman spectra,SEM,TEM,XRD,EDX and nonlinear absorption curves were characterized and measured.The results show that the Nb₂Al C carbide saturable absorber has high purity,good crystal structure,obvious nonlinear optical properties,and absorbance near 2μm band.Secondly,on the basis of the theoretical study of passively Q-switched,a passively Q-switched Tm:YLF laser based on Nb₂Al C device was built,and its output parameters were studied deeply.An 1.8-W average output power and a 1.4μs pulse duration at 162k Hz were obtained from a passively Q-switched Tm:YLF laser,and a 10.30-μJ pulse energy was achieved in the experiment,corresponding to a central output wavelength of1899.6 nm and an optical-optical conversion efficiency of 15.45%.In addition,beam quality factors less than 1.10 in x-axis direction and y-axis direction were achieved from the passively Q-switched Tm:YLF laser.Finally,based on the passively mode-locked theory,a passively mode-locked Tm:YLF Z-shaped folded cavity laser based on Nb₂Al C was realized.With an incident pump power of 21.63 W,a 0.379-W average output power and a 200-ps pulse width were achieved at 1872.1 nm,corresponding to a per pulse energy of 3.15 n J and a peak power of 15.75 W.In addition,the beam quality factors M_x²/M_y²were measured to be1.04 and 1.05.