title: Femtosecond laser fabrication of phase-shifted Bragg grating waveguides in fused silica.
abstract: Phase-shifted Bragg grating waveguides (PSBGWs) were formed in bulk fused silica glass by femtosecond laser direct writing to produce narrowband (22±3)  pm filters at 1550 nm. Tunable π and other phase shifts generated narrow passbands in controlled positions of the Bragg stopband, while the accurate placement of multiple cascaded phase-shift regions yielded a rectangular-shaped bandpass filter. A waveguide birefringence of (7.5±0.3)×10(-5) is inferred from the polarization-induced spectral shifting of the PSBGW narrowband filters.
authors: Institute for Optical Sciences and the Department of Electrical and Computer Engineering, University of Toronto, 10 King’s College Road, Toronto, Ontario M5S 3G4, Canada. j.grenier@utoronto.ca
authors: Jason R
authors: JR
authors: Grenier
authors: Luís A
authors: LA
authors: Fernandes
authors: J Stewart
authors: JS
authors: Aitchison
authors: Paulo V S
authors: PV
authors: Marques
authors: Peter R
authors: PR
authors: Herman