离轴三反光纤阵列激光三维成像发射系统

离轴三反光纤阵列激光三维成像发射系统中,大功率激光器发出的激光经阵列光纤分束,由光纤的芯径和单元发散角计算离轴三反光学系统的焦距,由光纤的数值孔径确定系统的入瞳直径范围,光纤阵列的长度决定了光学系统的发射总视场。离轴三反光学系统采用正向设计、反向使用的思路,将光纤阵列置于离轴三反光学系统焦面位置,反向追迹光线,可以得到光纤阵列上各元激光经光学系统后的高斯光束发散角大小和相邻元之间的角度关系。文中的设计实例实现了51元激光,每一元以20 rad的较小发散角出射,实例表明,该发射系统能实现多元激光微弧度量级的发散角出射,在目标面上形成间隔均匀、圆对称性良好的足印光斑。该发射系统在设计的发射总视场内,理论上不存在波束数的限制,这是区别于其他发射系统的另一优势。

Emitting system of fiber-array 3D laser imaging using off-axis three-mirror system

A novel emitting system of fiber-array 3D laser imaging using off-axis three-mirror system was proposed. High-power laser was split to certain number of beams by fiber splitting and output with fiber-array. The off-axis three-mirror was designed as normal telescope system, and its focus length was the divergence angle divided by the core diameter of the fiber, while the F number in image space was determined by the Numerical Aperture(NA) of the fiber. The total field of view was the focus length divided by the length of the fiber-array. The fiber-array was set on the focus plane of the off-axis three-mirror system, and rays were traced in the opposite way of design. The example system realized divergence angle as 20 rad of 51 fiber beams, and it showed that the divergence angle of every fiber beam satisfied the target value well and the footprint between the neighbouring beams has good uniformity on the target surface. Besides, this emitting system was suitable for any number of laser beams within the total design field of view.