Optimization of single-mode sapphire waveguide Bragg gratings

We demonstrate the fabrication and optimization of waveguide Bragg gratings on single-crystal sapphire substrates using femtosecond laser direct writing. The gratings are fabricated using modulated bursts and are embedded inside single-mode depressed cladding waveguides. Through design optimization,...

Descripció completa

Dades bibliogràfiques
Autors principals: Wang, M, Salter, PS, Payne, FP, Liu, T, Shipley, A, Song, Z, Morris, SM, Booth, MJ, Fells, JAJ
Format: Journal article
Idioma:English
Publicat: IEEE 2024
Descripció
Sumari:We demonstrate the fabrication and optimization of waveguide Bragg gratings on single-crystal sapphire substrates using femtosecond laser direct writing. The gratings are fabricated using modulated bursts and are embedded inside single-mode depressed cladding waveguides. Through design optimization, and fabrication parameter tuning, a depressed cladding waveguide with a loss of ∼0.8 dB/cm and a Bragg grating with a reflectivity of higher than 90% in the telecommunications wavelength band are demonstrated. The waveguide Bragg grating exhibits stable thermal properties under annealing at 1200°C. A sampled grating and a grating array are also demonstrated, showing the potential for more complex grating designs.