[1] [1] M W Beijersbergen, R P C Coerwinkel, M Kristensen, et al.. Helical-wavefront laser beams produced with a spiral phaseplate[J]. Opt Commun, 1994, 112(5-6): 321-327.

[2] [2] S N Khonina, V V Kotlyar, M V Shinkaryev, et al.. The phase rotor filter[J]. J Mod Opt,1992, 39(5): 1147-1154.

[3] [3] P A M Dirac. Quantized singularities in the electromagnetic field[J]. Proc R Soc Lond A, 1931, 133(821): 60-72.

[4] [4] J F Nye, M V Berry. Dislocations in wave trains[J]. Proc R Soc Lond A, 1974, 336(1605): 165-190.

[5] [5] J Wang, J Yang, I M Frazal, et al.. Terabit free-space data transmission employing orbital angular momentum multiplexing[J]. Nature Photon, 2012, 6: 488-496.

[6] [6] A Niv, G Biener, V Kleiner, et al.. Formation of linearly polarized light with axial symmetry by use of space-variant subwavelength gratings[J]. Opt Lett, 2003, 28(7): 510-512.

[7] [7] K Sueda, G Miyaji, N Miyanaga, et al.. Laguerre-Gaussian beam generated witha multilevel spiral phase plate for highintensity laser pulses[J]. Opt Express, 2004, 12(15): 3548-3553.

[8] [8] C S Guo, D M Xue, Y J Han, et al.. Optimal phase steps of multi-level spiral phase plates[J]. Opt Commun, 2006, 268(2): 235-239.

[9] [9] P Schemmel, G Pisano, B Maffei. Modular spiral phase plate design fororbital angular momentum generation atmillimetre wavelengths[J]. Opt Express, 2014, 22(12): 14712-14726.

[10] [10] B Chen, L R Guo, J Y Tang, et al.. Refractivemicrolens arrays with parabolic section profile and no deadarea[C], SPIE,1996, 2866: 420-423.

[11] [11] B Chen, L R Guo, J Y Tang, et al.. Novel method formaking parabolic grating[C]. SPIE,1996, 2687: 142-149.

[12] [12] C L Du, X C Dong, C K Qiu, et al.. Profile control technology for high performance microlens array[J]. Opt Eng, 2004, 43(11): 2595-2602.

[13] [13] L F Shi, X C Dong, Q L Deng, et al.. Formation for bass-relief micro-profiles based on an analytic formulation[J]. Chin Phys Lett, 2007, 24(10): 2867-2869.

[14] [14] L F Shi, C L Du, X C Dong, et al.. Effective formation method for an aspherical microlensarray based on an aperiodic moving mask during exposure[J]. Appl Opt, 2007, 46(34): 8346-8350.