激波对激光束远场强度分布影响的数值研究

Numerical study of the far-filed intensity distribution of laser beam disturbed by shock wave

研究了半径0.1m、焦距106m、波长分别为10.6μm、1.315μm的激光束通过具有激波结构的超声速绕楔流场后的远场强度分布。得到了沿光束传播方向积分的流场的光程差分布以及激光束在穿过超声速绕楔流场并在无扰来流中传播1km后光束的强度分布。结果表明:强的激波结构使激光束远场强度分布发生了向光程增大方向的明显偏折,对于波长不同的激光束得到光束通过流场后的远场强度分布不同。

The far-field intensity distributions of laser beam is discussed which radius are 0.1m,focus length is 10~6m and wavelength is 10.6μm or 1.315μm when it pass through the supersonic wedge flow. The optical path difference(OPD) of flow field was obtained. Also the intensity distribution of laser beam when it pass through wedge flow field and transmit 1km in inflow was obtained. Result shows that laser beam deflects to the direction which optical path length increase. The far-field intensity of laser beam is not the same for the difference of wavelength.