Loss Mechanisms of Optical Waveguides Inscribed in Fused Silica by Femtosecond Laser Direct Writing

• Type: Article in International Scientific Journal
• Date: 2019

Authors

Amorim, VA (Author) Other; Maia, JM (Author) Other; Viveiros, D (Author) FCUP; Marques, PVS (Author) FCUP

Journal

Title: Journal of Lightwave Technology

Vol. 37

Pages: 2240-2245

ISSN: 0733-8724

Publisher: Optical Society of America

Indexing

ISI Web of Knowledge - 23 Citations

Scopus - 24 Citations

Other information

Authenticus ID: P-00Q-8M9

DOI: 10.1109/jlt.2019.2900913

Abstract (EN): Optical waveguides directly written in fused silica using a femtosecond laser were characterized from 350 to 1750 nm to gain insight on the waveguide's loss mechanisms and their dependence on processing parameters, such as pulse energy, scan velocity, and annealing temperature. Two major loss mechanisms were identified. In the range of parameters tested, high pulse energy was seen to improve coupling losses at long wavelengths, while high scan velocity has a negative effect in both Rayleigh scattering and coupling losses at long wavelengths. Thermal annealing of the waveguides demonstrated an improvement of the Rayleigh scattering at a cost of higher coupling losses at long wavelengths. Wavelength independent Mie scattering was also observed, evolving negatively with pulse energy. A minimum Rayleigh scattering coefficient of approximate to 0.5 dB.cm(-1).mu m(4) (approximate to 0.08 dB.cm(-1).mu m(4) for thermally treated waveguides) together with a Mie scattering coefficient of approximate to 0.2-0.65 dB/cm are reported.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6