scholarly journals A Novel Focal Length Measurement Method for Center-Obstructed Omni-Directional Reflective Optical Systems

2019 ◽  
Vol 9 (11) ◽  
pp. 2350 ◽  
Author(s):  
Hojong Choi ◽  
Joo-Youn Jo ◽  
Jae-Myung Ryu
Keyword(s):  
Optical System ◽  
Measurement Method ◽  
Focal Length ◽  
Tolerance Analysis ◽  
Field Of View ◽  
Optical Systems ◽  
Wide Field ◽  
Surveillance Camera ◽  
Length Measurements ◽  
Design Software

An omni-directional optical system can be used as a surveillance camera owing to its wide field angle. In cases in which a system is designed with a central screen obscuring structure to increase the resolution of the off-axis field, however, the conventional methods cannot be used to measure the effective focal length (EFL). We assumed the actual and theoretical distortion values of the fabricated optical system to be the same and determined the system’s EFL by finding the minimum deviation point of the measured and theoretical distortions. The feasibility of the determined EFL was verified through a tolerance analysis of the system. For these precise measurements we also analyzed the sources of error. To verify our proposed measurement method, we measured the focal length of a center-obstructed omni-directional reflective optical system with an 80–135° field of view (FOV). The EFL from the measurement was 0.3739 mm and was only approximately 11 µm different from the EFL calculated using the design software. Thus, the reliability of focal length measurements in omni-directional optical systems was improved.

Design of Athermalized Infrared Telephoto Lens

2013 ◽  
Vol 552 ◽  
pp. 8-13
Author(s):  
Yu Zhang ◽  
Ji Yang Shang ◽  
Yue Xu ◽  
Wen Sheng Wang
Keyword(s):  
Image Quality ◽  
Optical System ◽  
Power Distribution ◽  
Focal Length ◽  
Diffraction Limit ◽  
Field Of View ◽  
Optical Systems ◽  
Modulation Transfer ◽  
Full Field ◽  
Telephoto Lens

IR optical system is much more appropriate to be applied in cluttered and formidable conditions. The change of temperature could degrade image quality of the infrared optical system. So the athermalization becomes the difficult part and key factor in the designing of MWIR optical systems for working under temperature range of -40°C~60°C. In this paper, the infrared telephoto lens is designed; it meets the designing requirements and has good image quality. The effective focal length is 240mm and the F-number is 2.The full field of view is 3.2°. In order to balance the chromatic aberration, an aspherical surface is used in the athermalized infrared optical system. Through carefully selected optical material and reasonable optical power distribution, passive optical athermalization can be realized. The curve of MTF is close to diffraction limit. Within the working temperature, the value of MTF at 30cy/mm is always large than 0.6. The results show that the modulation transfer function (MTF) of optical system in all field of view approaches the diffraction limit at different temperature, and 80% energy concentrates in 1 pixel.

scholarly journals Wide field-of-view crossed Dragone optical system using anamorphic aspherical surfaces

2018 ◽  
Vol 57 (15) ◽  
pp. 4171 ◽  
Author(s):  
Shingo Kashima ◽  
Masashi Hazumi ◽  
Hiroaki Imada ◽  
Nobuhiko Katayama ◽  
Tomotake Matsumura ◽  
...  
Keyword(s):  
Optical System ◽  
Field Of View ◽  
Wide Field ◽  
Wide Field Of View

scholarly journals Optical Design of the Goaly3 Multi-Mirror Telescope System with a Wide Field of View

2021 ◽  
Vol 11 (3) ◽  
pp. 1200
Author(s):  
Junliu Fan ◽  
Quanying Wu ◽  
Baohua Chen ◽  
Lin Liu ◽  
Lei Chen
Keyword(s):  
Fill Factor ◽  
Optical Design ◽  
Tolerance Analysis ◽  
Field Of View ◽  
Wide Field ◽  
Aspheric Surfaces ◽  
The Monte Carlo Method ◽  
Wide Field Of View ◽  
Mirror Telescope ◽  
Telescope System

A Golay3 multi-mirror telescope (MMT) system is designed in this paper. The fill factor of the Golay3 MMT is derived from the angular resolution of the telescope. An initial configuration is established according to the paraxial optical theory. A three-element aspheric corrector group is designed and placed in the converging light cone to enlarge the field of view (FOV) of the Golay3 MMT. The tolerance analysis for each surface of the Golay3 MMT is conducted using the Monte Carlo method. The design results show the FOV of the Golay3 MMT system can be increased to 1.5° with the insertion of a three-element aspheric corrector group. The results of the tolerance analysis indicate that most tolerances are loose, while some decenter tolerances relating with the aspheric surfaces are relatively tight, but still within an acceptable range.

Optical Design of Off-Axis Four-Mirror Optical System with Wide Field of View

2013 ◽  
Vol 33 (10) ◽  
pp. 1022002
Author(s):  
刘军 Liu Jun ◽  
刘伟奇 Liu Weiqi ◽  
康玉思 Kang Yusi ◽  
吕博 Lü Bo ◽  
冯睿 Feng Rui ◽  
...  
Keyword(s):  
Optical System ◽  
Optical Design ◽  
Field Of View ◽  
Wide Field ◽  
Wide Field Of View

Design of Wide Field-of-View and Multi-Targets 3D Imaging Optical System with Coaxial Five Mirrors

2018 ◽  
Vol 38 (6) ◽  
pp. 0608001
Author(s):  
刘莹奇 Liu Yingqi ◽  
骆媛 Luo Yuan ◽  
鲁华 Lu Hua ◽  
梅甫麟 Mei Fulin ◽  
舒营恩 Shu Ying’en
Keyword(s):  
Optical System ◽  
3D Imaging ◽  
Field Of View ◽  
Wide Field ◽  
Wide Field Of View

Wide Field of View Turbulence Profile Measurement Method

2018 ◽  
Vol 45 (8) ◽  
pp. 0804003
Author(s):  
方玉亮 Fang Yuliang ◽  
金振宇 Jin Zhenyu ◽  
刘忠 Liu Zhong ◽  
李正刚 Li Zhenggang
Keyword(s):  
Measurement Method ◽  
Field Of View ◽  
Profile Measurement ◽  
Wide Field ◽  
Wide Field Of View

Design of infrared optical system with super-long focal length and dual field-of-view

2014 ◽  
Vol 7 (4) ◽  
pp. 631-637
Author(s):  
白玉琢 BAI Yu-zhuo ◽  
木锐 MU Rui ◽  
马琳 MA Lin ◽  
贾钰超 JIA Yu-chao ◽  
普群雁 PU Qun-yan ◽  
...  
Keyword(s):  
Optical System ◽  
Focal Length ◽  
Field Of View
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