Experiments and analyses of a new type optical system for computed radiography

A new high-performance laser scanning system is designed. In this system, a scanning arm consisting of a pentagonal prism and a scanning object lens is used to replace the traditional Fθ lens, and a circular imaging plate transmission mechanism is specially designed in order to meet the requirement of the scanning arm. At the same time, the stimulation fluorescence can be obtained by the scanning arm. Some main factors that influence the spatial resolution and the performance of the laser scanner system are analyzed, and the analysis results are presented, which is helpful for further optimization design of the system. Experimental results indicate that the images obtained by the system have good visual effects and can meet the requirements of industrial inspection.     

混合教学模式在《光电仪器电子学实验》中的运用探索

高等学校实验教学承担着培养学生实践能力、创新能力和综合素质的重要任务。传统的实验教学模式在实验内容设置和安排上缺乏对学生自主研究、深度参与及提高综合能力的考虑,因而不利于学生个性和创新精神的养成。以《光电仪器电子学实验》课程为例提出了线上线下双反馈一体化的混合式实验教学模式。通过线上线下双反馈一体化的实验教学模式,可以形成一个发现问题、及时反馈、调整实验教学方案、跟踪评价并持续改进的闭环教育过程,有效提高学生学习的自主性、积极性,提高学习效果。     

惠斯通电桥实验中高灵敏度档位下最佳桥臂电阻的探讨

惠斯通电桥的灵敏度与检流计的灵敏度有关,当检流计灵敏度档位是4×10~(-6)A/格和4×10~(-8)A/格时惠斯通电桥比较容易调节平衡,但是当检流计灵敏度档位是4×10~(-9)A/格时,惠斯通电桥很难调节到平衡的状态。为了解决高灵敏度档位下惠斯通电桥难以调节到平衡的问题,我们在高灵敏度档位的前提下研究了桥臂比和桥臂电阻对实验测量和相对不确定度的影响。当桥臂比R_1/R_2=1/10时,任意的桥臂电阻都可以使电桥平衡,从而测量出待测电阻的阻值。当桥臂比R_1/R_2=1/1时,桥臂电阻处于11 000Ω至13 000Ω时电桥可以调节到平衡。     

癌变对上皮组织前后向散射特性影响的对比研究

Mueller矩阵成像法可用于获取生物组织的微观结构信息,在组织早期癌变的诊断中发挥着重要作用。采用不同的成像方式得到的结果往往具有很大的差异。为了保证Mueller矩阵成像法对组织癌变诊断结果的可靠性,需要明确成像方式不同对检测结果的影响。建立了正常和癌变上皮组织散射模型,利用Monte Carlo仿真法对比研究了癌变对上皮组织前向和后向散射特性的影响。仿真结果表明,采用前向散射成像方式时,去偏参量对组织状态的改变比较敏感,但去偏参量随组织癌变的发展并非单调变化;而采用后向散射成像方式时,相位延迟参量随组织状态的改变有显著变化,且相位延迟随组织癌变的发展单调减小。     

Design of a hyper-numerical-aperture deep ultraviolet lithography objective with freeform surfaces

We have proposed and developed a design method of a freeform surfaces(FFSs) based hyper-numerical-aperture deep ultraviolet(DUV) projection objective(PO) with low aberration. With an aspheric initial configuration,lens-form parameters were used to determine the best position to remove elements and insert FFSs. The designed FFSs PO reduced two elements without increasing the total thickness of the glass materials. Compared with aspheric initial configuration, the wavefront error of the FFSs PO decreased from 0.006λ to 0.005λ, the distortion reduced from 1 to 0.5 nm, and the aspheric departure decreased from 1.7 to 1.35 mm. The results show that the design method of the FFSs PO is efficient and has improved the imaging performance of PO. The design method of FFSs PO provides potential solutions for DUV lithography with low aberrations at 10–5 nm nodes.