Optimization design of a diffractive axicon for improving the performance of long focal depth

Abstract

An improved iterative approach is proposed to design a diffractive axicon with long focal depth and high lateral resolution. Model designs of the diffractive axicon are carried out in order to convert multi-wavelength uniform beam and Gaussian beam into long focal depth focusing. The numerical results indicate that the designed axicon can achieve long extended focal depth, high transverse resolution and diffraction efficiency simultaneously. Furthermore, a uniform plateau profile can be obtained by using multiple weighted algorithm. The axicon that generates two preset focal depths has been designed, which can also exhibit two perfect long focal depths.