High-speed, high-precision focal length measurement using double-hole mask and advanced image sensor software. (March 2018)

• Record Type: Journal Article
• Authors: Cao, Binh Xuan; Le Hoang, Phuong; Ahn, Sanghoon; Kim, Jeng-o; Kang, Heeshin; Noh, Jiwhan
• Is Part Of: ISA transactions. Volume 74(2018)
• Page Start: 239
• Page End: 244
• Publication Date: 2018-03
• Subjects: Focal length measurement -- Image sensor -- Double-hole mask -- Laser micromachining; Engineering instruments -- Periodicals; Engineering instruments; Periodicals; Electronic journals; 629.805
• DOI: 10.1016/j.isatra.2018.01.018
• Languages: English
• ISSNs: 0019-0578

Abstract

Abstract: A cutting-edge precision technique for computation of focal length of a positive lens with double-hole mask is described. The technique is simple and versatile due to incorporation of the updated functions of image sensor device that supports reading the distance between beam spots instantaneously while the position of the specimen is being changed, as well as the reduction in several challenging measurement steps. Furthermore, this technique does not require prior knowledge of distances in the optical setup. High accuracy in focal-length measurement is obtained by precise beam spot distance analysis using image sensor integrated software. The acquired data exhibit considerably high precision and reproducibility. Highlights: A new technique measures focal length of a positive objective lens. The pre-measurement of distances is completely ignored. The advancement of the image sensor contributes to precisely read beam spot distance. The experimental setup is compact and easy to operate. The obtained data demonstrate the high precision and reproducibility of the technique.