Fabrication of ultrathin flexible diffractive optical elements (DOEs) and application for laser speckle suppression. (December 2022)

• Record Type: Journal Article
• Authors: Le, Zichun; Liu, Zongshen; Qiu, Yujie; Ren, Hongliang; Dai, Yanxin
• Is Part Of: Optics and lasers in engineering. Volume 159(2022)
• Publication Date: 2022-12
• Subjects: Film-forming technique -- Ultrathin -- Flexible DOEs -- Acetone-PMMA and benzene-PMMA coating liquids -- Speckle suppression -- Transmittance; Lasers in engineering -- Periodicals; Optical measurements -- Periodicals; Optics -- Periodicals; Lasers en ingénierie -- Périodiques; Mesures optiques -- Périodiques; Optique -- Périodiques; 621.36605
• DOI: 10.1016/j.optlaseng.2022.107223
• Languages: English
• ISSNs: 0143-8166

Abstract

Highlights: A novel preparation method for acetone-PMMA and benzene-PMMA coating liquids was developed and demonstrated for manufacturing ultrathin flexible DOEs. A film-forming technique for ultrathin flexible diffractive optical elements (DOEs) was developed, and the thickness of 2.8μm was achieved for a flexible DOE with home-made benzene-PMMA coating liquid. An optical device based on a pair of the fabricated DOEs with reciprocating movement was applied for speckle suppression in an experimental imaging system. The speckle contrasts for red, green, and blue lasers decreased to 5%-7%, and the transmittances for DOEs increased to 88%-92%. Abstract: Compact and flexible optical components are expected to be utilized in laser-imaging systems. We introduce a novel technique for producing self-made ultrathin flexible diffractive optical elements (DOEs) with reciprocating movement that are effective in suppression of laser speckle. We developed a preparation method for acetone-PMMA and benzene-PMMA coating liquids, and obtained all the process parameters for producing ultrathin flexible PMMA DOEs. Experimental results revealed that the fabricated DOEs reduced the speckle contrasts for red, green, and blue lasers substantially; in addition, their transmittance increased significantly. The proposed techniques can be applied extensively in the development of other kind of flexible microoptics.