Study On The The Thermal Distortion And The Efficiency Of Far Field Of The Reflectors Irradiated By The High Power Laser

When building up and designing the high-power laser equipment, both the power density,the whole energy and improve the emission-beam’s quality are importance for satisfy requirements.High-power lasers may invalidation,as usual. In particular, thermal distortion will influence the phase and the vibrancy of lasers when high-power laser propagating and make the beam quality degradation.But the reflectors must be influenced by thermal distortion when the high-power laser equipment work,and the influence will aggravate when the power rising.So,the thermal distortion become the chiefly factor confining the beam quality of the high-power laser equipment,and it must be considering when build the high-power laser equipment.The main content of dissertation is as following:1、Established the reflectors’s models of the thermal distortions by high energy laser beam which irradiating with45°angle basic principles of thermal distortion with the finite-element method.The finite-element method gives of reflectors distortion are some discrete points.But other points must be considered with other methods.The finite-element method and the optics design combined by using the Zernike polynomials simulate the finite-element’s calculation result,so we can gained the whole info of the thermal distortions of the reflectors.2、The validity of the description of fluid flow and heat transfer in a microchannel heat sink using the Navier-Stoke equation and the heat conduction equation is discussed. The RNG k-ε turbulence model is used in the numerical simulation of the turbulent flow in a microchannel heat sink. Numerical simulations are carried out with45°irradiation angle, the result of the simulations show that the microchannel heat sink reflectors with the lower temperature grads and the fewer distortion.3、A new design, an Oxygen-free copper microchannel heat sink consisting of five copper sheets, is provided in this paper. The microchannel mirror can be fabricated by photolithography combined with laser manufacturing technique. The simulation results show that the thermal deformation of the mirror is very small and the multi-layer Cu mirror is an effective method to minimize the thermal effect.4、The influence of atmosphere for laser transmission is considered and firstly the far-field optical quality of laser is measured and the atmospheric transmissibility is calculated. The results show that the microchannel heat sink reflectors can ameliorate the far-field laser’s distribution. At last, the integration error analyses are implemented for the measured scheme of far-field energy distribution with laser.