针对癌细胞突变基因诱导荧光信号弱、光谱覆盖范围宽、现有显微镜不能检测等局限, 本文设计了光谱波段为450~800 nm、数值孔径为0.95的荧光显微物镜。物镜采用+ + -结构, 因宽光谱、大数值孔径像差校正难度大、透镜片数多、装调困难, 前组设置成敏感组分, 承载物镜装调的调校功能, 承担90%以上光焦度; 中间组为弱光焦度组分, 用于校正大数值孔径下的二级光谱, 显著降低了二级光谱校正元件的加工难度; 后组为负光焦度组分, 用于平像场和增大物镜的工作距离。物镜的设计参数为: 总长58 mm、工作距0.21 mm、视场0.625 mm、倍率40×、数值孔径0.95, 结果表明: 其像质接近衍射极限, 畸变小于0.2%, 满足多种癌细胞突变基因的弱信号生物监测设计要求。

Because the fluorescence signal induced by a cancer cell is weak and has a wide spectral range, along with the detection limits of existing microscopes, this paper proposes fluorescence microscope objectives with a spectral range of 450—800 nm and a numerical aperture of 0.95. The objective used “+ + -” structure because the correction of aberration, caused by a wide spectrum and high numerical aperture, is difficult. The objective must include a set number of lenses and the alignment process is difficult; the front group, considering more than 90% focal power, is set as the sensitive component, which is useful for adjusting the alignment process; the middle group is the weak focal component, which is used to correct the secondary spectrum caused by the large numerical aperture, so that the difficulty in manufacturing the apochromatic elements is reduced significantly. The posterior group is the negative component, which is useful for flattening the image field and increasing the working distance of the objective. The objective parameters are as follow: the total length is 58 mm, the working distance is 0.21 mm, the magnification is 40×, and the full field is 0625 mm. The results show that the image quality nearly reaches the diffraction limit and the distortion is less than 0.2%, meeting the surveilling requirements of the weak fluorescence signal from cancer cells.