Study On The Light Field Of More End-pumped Diode-pumped Solid-state Lasers

In recent years, Diode Pumped Solid State Laser (DPL)has become a hotspot in themost solid laser device, with its high efficiency, small volume, light weight, long life,good stability and other characteristics. DPL adopted end pumped, effectively couplingpumped light in TEM00with activated media, is easy to realize pump modulation andlaser cavity of pattern matching between light oscillation. With low threshold, theadvantages of efficiency, it is advantage to achieve good output beam quality.Focusing on end pumped DPL, this paper takes physical model of equivalenttreatment and algorithm design for its resonant cavity, makes the equivalent physicalmodel united(in parallel plane cavity for basic unit),modular (diffraction calculationmodule, gain distribution calculation module, thermal lens calculation module, lightfield magnification calculation module).Considering in the actual application of foldingspace of crystal number variable, We use the method of building block directaccumulation to form a kind of loops and automatic chain organization way inprogramming process. Put forward a resonant cavity beam calculation method based onthe Fresnel-Kirchhoff diffraction integral. Considering the effect of the medium’sthermal lens benefits on the light field, we establish the approximate calculation modelof the gain distribution of the active medium, and complete the simulation calculationprogram of DPL more end pump. Using the simulation program, we can approximatecomputation out different parameters of the resonator light field distribution and opticalfield magnification. This software of light field calculation has not been reported in anyliterature at present.Using the software, the paper launches the discussion on heating effect ofaxisymmetric and non-axisymmetric distribution situation, emphasizes the distributionrule of three end pumped DPL resonator light field.Under the influence of the heatingeffect of the distribution of axial symmetry:①Along with the increase of the pumppower, optical field has a great influence;②The optical field enlargement factorchanges along with the pump light radius increases,only when the pump light radiussatisfies certain conditions, the resonant cavity can start of oscillation, andsimultaneously pump light radius exist optimum value;③When total length of cavityinvariable, changing relative length of some parts has enormous influence on the opticalfield enlargement factor. Under the influence of non-axial symmetry distributed thermalreaction, with other parameters invariable.①Along with pump power increasing, the optical field enlargement factor reduces gradually;②Comparing with the conditionreferring to axial symmetry distribution which has the same parameters, the optical fieldenlargement factor reduces obviously, the optical field distribution come out distortion.And when farther deviated from center of the resonant cavity, more serious thedistortion will be.