Design of a high-resolution high-magnification MWIR continuous zoom lens system

2021 ◽  
Author(s):  
Thanh Dat Vu ◽  
Xuan Du Dang ◽  
Dat Nguyen-Van
Author(s):  
Bertholdand Senftinger ◽  
Helmut Liebl

During the last few years the investigation of clean and adsorbate-covered solid surfaces as well as thin-film growth and molecular dynamics have given rise to a constant demand for high-resolution imaging microscopy with reflected and diffracted low energy electrons as well as photo-electrons. A recent successful implementation of a UHV low-energy electron microscope by Bauer and Telieps encouraged us to construct such a low energy electron microscope (LEEM) for high-resolution imaging incorporating several novel design features, which is described more detailed elsewhere.The constraint of high field strength at the surface required to keep the aberrations caused by the accelerating field small and high UV photon intensity to get an improved signal-to-noise ratio for photoemission led to the design of a tetrode emission lens system capable of also focusing the UV light at the surface through an integrated Schwarzschild-type objective. Fig. 1 shows an axial section of the emission lens in the LEEM with sample (28) and part of the sample holder (29). The integrated mirror objective (50a, 50b) is used for visual in situ microscopic observation of the sample as well as for UV illumination. The electron optical components and the sample with accelerating field followed by an einzel lens form a tetrode system. In order to keep the field strength high, the sample is separated from the first element of the einzel lens by only 1.6 mm. With a numerical aperture of 0.5 for the Schwarzschild objective the orifice in the first element of the einzel lens has to be about 3.0 mm in diameter. Considering the much smaller distance to the sample one can expect intense distortions of the accelerating field in front of the sample. Because the achievable lateral resolution depends mainly on the quality of the first imaging step, careful investigation of the aberrations caused by the emission lens system had to be done in order to avoid sacrificing high lateral resolution for larger numerical aperture.


2021 ◽  
Vol 27 (1) ◽  
pp. 181-188
Author(s):  
Yuanyuan Jiang ◽  
Jiangrong Peng ◽  
Yunpeng Cao ◽  
Zhiqiang Han ◽  
Ling Zhang ◽  
...  

2013 ◽  
Vol 52 (4) ◽  
pp. 862 ◽  
Author(s):  
Antonín Mikš ◽  
Jiří Novák
Keyword(s):  

2012 ◽  
Vol 571 ◽  
pp. 324-327
Author(s):  
A Qi Yan ◽  
Deng Shan Wu ◽  
Hao Wang ◽  
Jian Zhong Cao ◽  
Jing Jin Ma ◽  
...  

Infrared zoom lens system with cooled focal plane array (FPA) detector is widely used in military application. Relevant information about optical design can be got easily, but research on infrared zoom lens system with low cost and high image quality for commercial application is less. This paper design a Compact infrared zoom lens system with only four lenses, using an uncooled focal plane array (FPA) with 384×288 pixels with zoom ratio 3:1. Because of large F number and less lenses, transmission of the whole zoom system is greatly improved. NETD and MRTD of infrared system will be satisfying by this compact design. There is no special surface such as diffractive surface, HOE in zoom lens system, and only Ge and Znse infrared materials are chosen which result in lower production cost of infrared zoom lens system for commercial applications.


2000 ◽  
Vol 8 (2) ◽  
pp. 16-17
Author(s):  
Mary Mager

After an inquiry from the Microscopy Listserver, I went back to my 1980 copy of Scanning Electron Microscopy, volume I. Several authors had investigated the structure of thin metal films by depositing the films onto carbon-film-covered TEM grids and imaging the films at high magnification. There were several proposals for new devices that have since become standards for high-resolution coaters, but the Listserver inquiry was for a fine conducting film suitabie for high-resolution SEM from an existing sputter coater.There were several factors studied that influenced the fine structure of the films. The first was the materials sputtered: for a given set of conditions of voltage, current and time, platinum gave the finest film, 60% gold-40% palladium (Au/Pd) the next finest and pure gold the least fine.


2011 ◽  
Vol 383-390 ◽  
pp. 4889-4894
Author(s):  
Zhi Qin Huang ◽  
Pei Ying Quan ◽  
Jin Li Zhang

In the past half century, the camera industry has developed very rapidly, which drove the optical lens and optical zoom technology to make great progress. The zoom lens’ technology principle of current mainstream optical zoom lens system is achieved by adjusting the relative position of the lens, objects and the focus. This paper takes the double-liquid zoom lens based on electric wet effect as the basis , the new zoom optical system is designed to achieve motor control without mechanical movement, then the vision correction is designed by using liquid lens, such as the correction of myopia and hyperopia, which can automatically identify the eyes degrees of myopia and hyperopia, avoid frequent replacement lens steps when optometry is done for eyes.


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