Study Of 914nm LD End Pumped Electro-optic Cavity Dumping All Solid State Laser

High repetition rate and large energy narrow pulse width solid state laser has been widely used in laser industry,ultra long distance measurement,photoelectric radar and laser confrontation,because of its advantages of high repetition frequency,narrow pulse width and high peak power.For example:used in the processing industry to complete drilling,welding,cutting,and rapid prototyping;used in radar detection for remote sensing,imaging,mapping,etc.;used as light communication,light storage and light information processing in the IT industry.In modern scientific research,it is widely used in laser fusion and spectral analysis.It is very significant to study the chemical reaction and so on.The aim of this study is to achieve a compact structure,a repetition rate of kHz,a single pulse energy greater than 5mJ,and a pulse width of less than 5ns.The development and current situation of all solid state lasers are developed and investigated.Starting from the four level rate equation theory of the 1064nm laser spectrum line,the effect of the pump light field and the distribution characteristics of the oscillating light field on the LD end pumped laser and the effect of mode matching on the output power and the oblique efficiency of the laser are analyzed.The 914nm semiconductor laser with optical fiber coupling output is used as the pump source to improve the quantum efficiency;the effect of the thermal lens effect is reduced by using the low doped Nd:YVO₄ crystal with low absorption coefficient of the pump wavelength,and the double crystal series connection structure is used to ensure that the crystal fully absorbs the pump light;by optimizing the pump light and oscillation.The mode matching parameters of the light enhance the efficiency of the optical conversion of the laser.Through theoretical analysis and experimental research,the parameters such as the length of the resonant cavity,the best pump position and the trigger delay are optimized to achieve the high frequency and large energy narrow pulse width laser.By reducing the effect of the thermal lens and ensuring the good pattern matching between the oscillating light and the pumping light,the output of 1064 nm line polarization pulse laser with high repetition rate,high energy and narrow pulse width is realized in this paper.The 914nm optical fiber coupled semiconductor laser end pumped Nd:YVO₄ crystal and BBO Pu box as electro-optic switch.Under the condition of repeated frequency 7kHz,when the resonator cavity is long 450mm and the absorption power of the crystal is 79.6W,the pulse width 4ns,the single pulse energy 5mJ,the maximum average output power 35W,the peak power 1.25MW,the beam quality M² are 1.58 stable pulse laser output,and the corresponding optical conversion efficiency is 44%.