Optical imaging systems play an extremely important role for humans in exploring the world, but the existence of chromatic aberration greatly reduces the imaging ability. Conventional optical systems require the combination of multiple lenses to reduce chromatic aberration, but such a solution is not conducive to the miniaturization and weight reduction of the optical system. In this paper, we design dual-wavelength multilevel diffractive lenses that focus pairs of wavelengths on the same focal plane, using a modified direct-binary-search algorithm to maximize the focusing efficiency. The simulated focusing efficiencies are 72% (92%) and 79% (92%) at the wavelength of 1.064 μm and 1.55 μm, respectively, for the two-dimensional (one-dimensional) ones. Through this approach, the results presented here suggest good focusing performance at two wavelengths, providing a new opportunity for various applications in dual-wavelength imaging systems and lightweight collimators.

光学成像系统在人类探索世界中扮演着极其重要的角色，但是色差的存在极大地降低了成像能力。传统的光学系统需要多个透镜的组合以减小色差，但是这种解决方案不利于光学系统的小型化和轻量化。在本文中，我们设计了一种双波长多级衍射透镜，它使用改进的直接二分查找算法将聚焦在同一焦平面上的成对的波长聚焦，以最大程度地提高聚焦效率。模拟的聚焦效率是在1.064波长72％（92％）和79％（92％）μ m和1.55 μm分别表示二维（一维）。通过这种方法，这里提出的结果表明在两个波长下都具有良好的聚焦性能，这为双波长成像系统和轻型准直仪中的各种应用提供了新的机会。