Stress induced birefringence tuning in femtosecond laser fabricated waveguides in fused silica

• Autor(a) principal: Paulo Vicente Marques
• Data de Publicação: 2012
• Outros Autores: Luís André Fernandes, Jason R. Grenier, Peter R. Herman, J. Stewart Aitchison
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://repositorio.inesctec.pt/handle/123456789/3383; http://dx.doi.org/10.1364/OE.20.024103

Femtosecond laser exposure produces form and stress birefringence in glasses, mainly controlled by laser polarization and pulse energy, which leads to challenges in certain applications where polarization mode dispersion or birefringence splitting is critical for the desired responses from optical devices. In this paper, parallel laser modification tracks with different geometries were applied to preferentially stress the laser-written waveguides and explore the possibility of tuning the waveguide birefringence in devices fabricated in bulk fused silica glass. Polarization splitting in Bragg grating waveguides showed the laser modification tracks to controllably add or subtract stress to the pre-existing waveguide birefringence, demonstrating independence from the nanograting induced form birefringence and the contributions from material stress. Stressing bars are shown that offer tunable birefringence in the range from ∼0 up to 4.35 × 10−4, possibly enabling great flexibility in desig