Comparison of supercontinuum generation in bulk sapphire and femtosecond-laser-inscribed waveguides. (February 2023)

• Record Type: Journal Article
• Authors: Li, Yue; Wu, Jie; Zhou, Hao; Deng, Guoliang; Zhou, Shouhuan
• Is Part Of: Optics & laser technology. Volume 158:Part A(2023)
• Publication Date: 2023-02
• Subjects: Optical waveguides -- Optical device fabrication -- Sapphire -- Supercontinuum generation; Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2022.108908
• Languages: English
• ISSNs: 0030-3992

Abstract

Highlights: Compressed cladding waveguide in sapphire has been fabricated by femtosecond laser. The threshold for SCG is reduced about 15% in the waveguide compared with bulk. The SCG was enhanced by 2.56 times in the waveguide compared with bulk. Abstract: We reported that depressed cladding waveguides were successfully fabricated in the sapphire crystal using a femtosecond laser. In waveguides and bulk sapphire, experimental studies and comparisons of supercontinuum generation (SCG) have been carried out. The integrated intensity ratio of the supercontinuum generated by the waveguide with a radius of 36 μm(WGI) to bulk sapphire reaches 2.56:1(400 nm-1028 nm) when the input pulse energy of 7.3 μJ. The SCG threshold in the waveguide with a radius of 24 μm(WGII) is about 15 % lower than bulk sapphire. The results reveal that when compared to bulk sapphire, the SC's generation efficiency improves while the threshold in the waveguide decreases. Our work proves that femtosecond laser fabricated waveguide can enhance the light-matter interaction and has great potential for the SCG.