Laser & Optoelectronics Progress, Volume. 49, Issue 1, 11202(2012)
Discrete Complex Pupil Filter for Diffraction Limited Three-Dimensional Optical Tube Field
A discrete complex pupil filter is proposed to create focused field using cylindrical beams in the high numerical aperture (NA) system. The radius of this filter is normalized to 1. It consists of six discrete transmitted annular zones with different amplitudes and there zones are shifted by a π phase retardation in neighboring zones except for the same retardation in the two outermost zones. The polarization pattern and intensity of the incident azimuthally polarized beam can be modified by the filter and then focused by the high NA lens. An ultra-long (longer than 8λ) diffraction limited three-dimensional optical tube with azimuthal polarization spiraling around z-axis can be created. The center of the optical tube field is null along the axial direction. And the radius of the tube determined by the transverse full width at half maximum (FWHM) of this focused field is 0.31λ in the focal plane and remains nearly constant throughout the total depth of the tube. This complex pupil filter will meet applications in three-dimensional tailoring of focused field and trapping and manipulation of particles.
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Liu Qingliang, Wang Jiming, He Chongjun, Liu Youwen. Discrete Complex Pupil Filter for Diffraction Limited Three-Dimensional Optical Tube Field[J]. Laser & Optoelectronics Progress, 2012, 49(1): 11202
Category: Instrumentation, Measurement and Metrology
Received: Jul. 10, 2011
Accepted: --
Published Online: Oct. 21, 2011
The Author Email: Qingliang Liu (mumapiaoyun@126.com)