5 × 5 Spot array based on two crossed single-groove gratings. Issue 9 (21st May 2019)

• Record Type: Journal Article
• Authors: Lu, Yunkai; Zhou, Changhe; Xiang, Changcheng; Wu, Jun; Yu, Junjie
• Is Part Of: Journal of modern optics. Volume 66:Issue 9(2019)
• Page Start: 998
• Page End: 1004
• Publication Date: 2019-05-21
• Subjects: Diffractive optics -- diffraction gratings -- spot array; Optics -- Periodicals; 535
• DOI: 10.1080/09500340.2019.1597195
• Languages: English
• ISSNs: 0950-0340

Abstract

ABSTRACT: Compared to the reported 5 × 5 spot arrays, we propose a way of generating a 5 × 5 spot array with much higher efficiency and better uniformity by using two crossed single-groove gratings. Normally, a single-groove grating cannot generate a 1 × 5 equal-intensity array by employing traditional Fourier optics theory. In this letter, we will show by vector diffraction theory that when the period of a single-groove grating is more than twice that of the incident wavelength, it may generate a 1 × 5 equal-intensity array. Based on this discovery, we expand the 1 × 5 array into a 5 × 5 spot array straightforwardly by using two crossed single-groove gratings. The dependence on the refractive index for producing a 1 × 5 equal-intensity array is interesting and we explain the phenomenon from the perspective of energy distribution by the simplified modal method.