Study On Compact Nanosecond Laser

Diode-pumped solid state laser(DPSSL)has become a research hotspot at home and abroad because of its small size,light weight,and high efficiency.It has been widely used in many fields such as science and technology,medical treatment,industry,and military.Solid-state nanosecond lasers have the advantages of high peak power,ease of implementation,and good stability.They are used in automotive systems,laser radar systems,and aerospace systems.Currently,the main technology for laser Q-switching is the passive Q-switching of semiconductor saturable absorption mirrors(SESAM)or electro-optic,acousto-optic active Q-switching techniques.The preparation of SESAM requires expensive and complicated epitaxial growth techniques and cumbersome post-processing processes,and the production cost is high.People have been committed to exploring new saturable absorbers to replace SESAM.Exploring new saturable absorbers is an important part of laser physics and laser technology.On the one hand,passive Q-switched lasers based on new saturable absorbers are studied on the one hand,and active Q-switched lasers based on acousto-optic modulators are studied on the other hand.On this basis,a high performance small nanosecond laser prototype is studied.The main research work of this article is as follows:1.Heterojunction saturable absorbing material of black phosphorus and graphene with heavy water as solvent was prepared,and the nonlinear characteristics of the material were studied.The results showed that the difference between black phosphorus and graphene with heavy water as solvent The stability of the saturable absorber is significantly better than that of black phosphorus,with a saturable modulation depth of 8.7%at 1064 nm.The passive Q-switched laser based on the saturable absorber is studied in this thesis.The Q-switched laser with the center wavelength of 1064nm,the highest repetition frequency of 255kHz and the narrowest pulse width of 233ns is obtained.2.Developed a prototype of a small nanosecond laser,which includes the use of zemax software to simulate the light emitting characteristics of the semiconductor laser and the design of the coupling light path.Solidworks software was used to design the mechanical parts and adjust the light path of the laser system.The prototype volume is 200mm×100mm×70mm,the repetition rate is adjustable from1-30kHz,the maximum output power is 1.7W in the heavy frequency range,the power fluctuation is less than 1%,the narrowest pulse width is 41ns,and the maximum single pulse energy is 170μJ The maximum peak power is 2.4 kW,the meridian M~2 factor is 1.27,and the Sagittal direction M~2 factor is 1.37.