激光聚变冲击波被动式测速光学系统设计

针对激光聚变装置冲击波速度被动测量的需求,设计了一种测速光学系统。采用高紫外透过率的氟化玻璃,实现了透射式300～800nm复消色差设计。系统光路具有前后两组镜头,中间为平行光,镜头间距可变,光路适应能力强。系统前端两侧的双目机器视觉能够完成自动寻的。平行光路中设置5个激光器,轴上的1个前向照明靶点用来观察条纹相机狭缝处的目标像质,轴外的4个与光轴平行后向传输用来标识系统光轴的位置,激光器部件可电动切入/切出。系统前组镜头F/#数为4,宽谱工作物方分辨率优于10μm,532nm单波长工作物方分辨优于5μm。该光学系统光路排布灵活,可单独被动测速,也可与主动测速系统VISAR耦合构成主被一体复合测速系统,满足激光聚变装置冲击波测速的需求。

Optical system for passive laser fusion shock wave velocity measurement

To meet the increasing demands of Inertial Confinement Fusion (ICF) shock velocity passive measurement, an optical collection system was designed. The 300-800 nm apochromatic optical system was designed using fluoride optical glasses, which have high transmission in the ultraviolet band. The imaging system has two lenses. The light beams between the two lenses were parallel, and the distance between the lenses could be varied to meet the size demands for different assembly positions. The machine visions on both sides of the first lens permit the system to achieve automatic homing. Five parallel laser beams were produced with one of them being on axis and lighting the target to obtain a clear image on the slit of the streak camera, and the other four surrounding the axis, lighting the second lens and focused on the imaging plane. The position of the separated optical elements present after the second lens can be easily fixed with the focusing lasers. The five laser beams can be terminated or turned on automatically. The first lens has an aperture of F/#4.0, and the collection system has a 10 μm object space resolution in 300-800 nm, and a 5 μm object space resolution in 532 nm. This optical system can passively measure the shock velocity by collecting the spectral radiance of the target. It can also act as the common path to transmit the probe laser and receive the Doppler-shift singles of VISAR simultaneously. This optical system could meet the demand of measuring the ICF shock velocity.