Wide-Spectrum Microscope with a Long Working Distance Aspherical Objective Based on Obscuration Constraint.
We present an approach for an initial configuration design based on obscuration constraint and on-axis Taylor series expansion to realize the design of long working distance microscope (numerical aperture (NA) = 0.13 and working distance (WD) = 525 mm) with a low obscuration aspherical Schwarzschild objective in wide-spectrum imaging (λ = 400-900 nm). Experiments of the testing on the resolution target and inspection on United States Air Force (USAF) resolution chart and a line charge-coupled device (CCD) (pixel size of 14 μm × 56 μm) with different wavelength light sources (λ = 480 nm, 550 nm, 660 nm, 850 nm) were implemented to verify the validity of the proposed method.
Institute of Ultra-Precision Optoelectronic Instrument Engineering, Harbin Institute of Technology, Harbin 150001, China. weibo.wang@eng.ox.ac.uk.|Department of Engineering Science, University of Oxford, ParksRoad, Oxford OX1 3PJ, UK. weibo.wang@eng.ox.ac.uk.
Weibo
W
Wang
Institute of Ultra-Precision Optoelectronic Instrument Engineering, Harbin Institute of Technology, Harbin 150001, China. wangchao.hit@gmail.com.
Chao
C
Wang
Institute of Ultra-Precision Optoelectronic Instrument Engineering, Harbin Institute of Technology, Harbin 150001, China. liujian@hit.edu.cn.
Jian
J
Liu
Institute of Ultra-Precision Optoelectronic Instrument Engineering, Harbin Institute of Technology, Harbin 150001, China. jbtan@hit.edu.cn.
Jiubin
J
Tan
aspherical Schwarzschild objective; long working distance; low obscuration; wide-spectrum microscope