采用长焦距单透镜方案,研制了一种新型的高性能近红外平行光管。以单模光纤导出的近红外激光(λ=1053nm)为光源,设计了满足光强均匀性要求的准直物镜焦距,使用新型的近红外消光涂料消除了杂散光的影响,并运用双平板剪切干涉技术完成了平行光管的不可见光束调校。采用自制的1053nm近红外干涉系统测试了平行光管的光学质量,结果表明,准直后的出射光束波面峰谷值(PV)达到0.045λ,光强的均匀性达79.2%。
The near-infrared collimator,with ultra-diffraction limit plane wave and uniform light intensity distribution,plays an important role in the adjustment of near-infrared optical systems and the measurement of detector response uniformity.Using infrared laser exported by a single-mode fiber as the light source,some key technologies are discussed in this paper,including the calculation of collimating lens′ focal length,the selection of collimating lens,the stray light influence on the uniformity of light intensity distribution,the calibration of invisible light path,the test of exported wavefront and so on.The self-developed 1 053 nm near-infrared interferometer is applied to test the wavefront of collimating lens,and the stray light is absorbed by the novel near-infrared extinction paint.At last the installation and calibration of the collimator are implemented with a two-plate shearing interferometer.The experimental results show that the peak to valley(PV) of wavefront error is 0.045λ and the uniformity of light intensity distribution is 79.2%.