提出和发展了一种基于大数值孔径环形光锥照明的远场超分辨光学显微成像新方法,采用将发光二极管(LED)面光源、窄带滤光和环形光锥照明相结合的特种照明方式,实现超分辨显微成像.建立了大数值孔径环形光锥照明成像的物理模型,根据标量衍射理论,在不同环形光锥照明时,推导出光学显微系统像面衍射斑光强分布的理论计算公式;通过Matlab求解和绘图,得到衍射斑光强的分布图样,从理论上证明这一成像方法可以有效提高光学显微镜的分辨率;建立了相应的显微成像系统,通过实验验证了该方法可有效改善显微镜的成像质量,显著提高分辨率;在中心波长450 nm、环形光锥数值孔径1.125一1.25时,实验获得的分辨率至少优于150 nm,与理论研究结果相符合.从而证明了这一方法的可行性.
On the basis of narrow-band filtered annular light-cone illumination with high numerical aperture,a new far-field super-resolution optical microscopic imaging method is proposed,and its physical model is established.Using the scalar diffraction theory,the formula of diffraction intensity in the image plane is derived for annular light-cone illumination and imaging under different numerical apertures. The diffraction patterns are further simulated through the Matlab program,which demonstrates that such a method may significantly increase the microscopic imaging resolution.Experiments have been carried out on a self-build microscopic system,showing that a resolution can be achieved to be better than 150 nm under 450 nm light wavelength and 1.125-1.25 annular numerical apertures.The experimental results are in good agreement with the theoretical predictions,thus proving the feasibility of this microscopic imaging method.