Research On All-solid-state Nd:YAG1.3?m Mode-locked Laser

All-solid-state pulsed lasers have extremely important research and application value.Self-mode-locking is a practical technique which generates ultrashort pulses.Self-mode-locking technology was first used to generate femtosecond(fs)pulses.In recent years,it has been found that using self-mode-locking techniques can also produce picosecond pulses and with the rise of the picosecond laser processing industry,the research focus on self-mode-locking technology has begun to move towards the realization of picosecond(ps)pulsed lasers.Compared with other laser crystals(such as Nd:YVO4,Nd:GdVO4,etc),Nd:YAG crystals have many advantages,such as high thermal conductivity,large fluorescence line width,high damage threshold and low prices.It is a mature laser crystal.In addition,it is applicable in high-intensity pumping,and faciliates the realization of high power pulsed lasers.Therefore,it has important research value.In this paper,the author has taken the lead in researching Nd:YAG 1.3?m self-mode-locked lasers at home and abroad,laying a foundation for the future realization of high-power,small-size,productized Nd:YAG 1.3?m picosecond pulsed lasers.The foundation.The main contents of the paper are as follows:(1)The theories on self-mode-locking were studied and its processes,self-starting and dynamics were analyzed.On this basis,the influence of effective nonlinear intensity on the self-mode-locking steady output was investigated.(2)Experiments on Nd:YAG 1.3?m self-mode-locked laser were designed and conducted.Stable output of the self-mode-locked pulse was realized under the condition of low nonlinear refractive index.At the same time,the cavity parameters such as resonator cavity shape,cavity mirror parameters,cavity lengths,and coupling system were changed.Contrasting experiments were conducted to explore the stability of cavity parameters for self-locking mode pulse output,mode locking threshold,and optical-optical conversion efficiency.When the pump power is 15W,the mode-locked maximum average pulse power can reach 3.65W,with optical-optical conversion efficiency reaching 24.3%and the single pulse energy reaching 2.37nJ.(3)A stable 1.3?m Q-switched mode-locked pulse was achieved based on Nd:YAG/V:YAG.When the pump power was 15W,the maximum average pulse power,Q-switched mode-locked pulse repetition frequency,Q-switched envelope pulse width,and the mode-locked pulse width were 1.01W,4.6KHz,24.4ns,and 195ps,respectively.