[1] Curtis J E, Koss B A, Grier D G. Dynamic holographic optical tweezers[J]. Optics Communications, 207, 169-175(2002).

[2] Eriksen R L, Mogensen P C, Glückstad J. Multiple-beam optical tweezers generated by the generalized phase-contrast method[J]. Optics Letters, 27, 267-269(2002).

[3] Brouhard G J, Schek H T, Hunt A J. Advanced optical tweezers for the study of cellular and molecular biomechanics[J]. IEEE Transactions on Biomedical Engineering, 50, 121-125(2003).

[4] Chen W B, Zhan Q W. Field enhancement analysis of an apertureless near field scanning optical microscope probe with finite element method[J]. Chinese Optics Letters, 5, 709-711(2007). http://www.opticsjournal.net/Articles/Abstract?aid=OJ071212000012JfLiOl

[5] Chen G J, Zhou Q Q, Ji X M et al. Study on high-numerical-aperture-focused characteristics of vector beam produced by π phase plate[J]. Acta Optica Sinica, 34, 1226001(2014).

[6] Quabis S, Dorn R, Eberler M et al. Focusing light to a tighter spot[J]. Optics Communications, 179, 1-7(2000).

[7] Chen J, Zhan Q W. Tailoring laser focal fields with vectorial optical fields[J]. Acta Optica Sinica, 39, 0126002(2019).

[8] Hao X, Kuang C F, Wang T T et al. Phase encoding for sharper focus of the azimuthally polarized beam[J]. Optics Letters, 35, 3928-3930(2010).

[9] Mushiake Y, Matsumura K, Nakajima N. Generation of radially polarized optical beam mode by laser oscillation[J]. Proceedings of the IEEE, 60, 1107-1109(1972).

[10] Hell S. Stelzer E H K. Properties of a 4pi confocal fluorescence microscope[J]. Journal of the Optical Society of America A, 9, 2159-2166(1992).

[11] Richards B, Wolf E. Electromagnetic diffraction in optical systems, II. Structure of the image field in an aplanatic system[J]. Proceedings of the Royal Society of London Series A, 253, 358-379(1959).

[12] Davidson N, Bokor N. High-numerical-aperture focusing of radially polarized doughnut beams with a parabolic mirror and a flat diffractive lens[J]. Optics Letters, 29, 1318-1320(2004).

[13] Chen W B, Zhan Q W. Creating a spherical focal spot with spatially modulated radial polarization in 4pi microscopy[J]. Optics Letters, 34, 2444-2446(2009).

[14] Chang Q, Yang Y F, He Y et al. Study of the focusing features of spatial amplitude and phase modulated radially polarized vortex beams in a 4pi focusing system[J]. Acta Physica Sinica, 62, 104202(2013).

[15] Chen Z Y, Zhao D M. 4pi focusing of spatially modulated radially polarized vortex beams[J]. Optics Letters, 37, 1286-1288(2012).

[16] Liu J, Yang Y F, He Y et al. Amendment for tightly focusing of cylindrically polarized vortex beams[J]. Acta Photonica Sinica, 43, 200-205(2014).

[17] Youngworth K S, Brown T G. Focusing of high numerical aperture cylindrical-vector beams[J]. Optics Express, 7, 77-87(2000).

[18] Li W C, Yang Y F, He Y et al. Triple optical chain generated by tight focusing of azimuthally polarized higher-order Laguerre-Gauss vortex beams[J]. Acta Optica Sinica, 39, 0826002(2019).