Direct laser writing of depressed-cladding waveguides in extremely low expansion lithium aluminosilicate glass-ceramics. (June 2021)

• Record Type: Journal Article
• Authors: Lipatiev, Alexey; Fedotov, Sergey; Lotarev, Sergey; Naumov, Andrey; Lipateva, Tatiana; Savinkov, Vitaly; Shakhgildyan, Georgiy; Sigaev, Vladimir
• Is Part Of: Optics & laser technology. Volume 138(2021)
• Publication Date: 2021-06
• Subjects: Ultra-low expansion glass-ceramics -- Femtosecond laser direct writing -- Laser-induced vitrification -- Lithium aluminosilicate glass -- Depressed-cladding waveguide; Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2020.106846
• Languages: English
• ISSNs: 0030-3992

Abstract

Highlights: Depressed-cladding waveguides were laser-inscribed in low expansion glass-ceramics. Femtosecond laser-induced vitrification provides reducing the refractive index. Refractive index change in the depressed cladding is stable up to 600 °C. The propagation losses in the fabricated single-mode waveguide are 2.4 dB/cm. Abstract: We report on direct femtosecond laser writing of depressed-cladding optical waveguides in extremely low expansion lithium aluminosilicate glass-ceramics. The waveguide cladding was formed by space-selective vitrification of nanocrystals in laser-modified regions of glass-ceramics responsible for the negative refractive index change up to 0.005. The optical properties of the laser-written waveguides were evaluated in terms of near-field and far-field intensity distribution and propagation losses at the wavelength of 1064 nm. The possibility of single-mode waveguiding with the upper limit of propagation losses 2.4 or 2.7 dB/cm for vertically or horizontally polarized light, respectively, was demonstrated. The obtained results open up new frontiers in the laser-assisted fabrication of 3D optical waveguide circuits in the media with outstanding thermal stability.