Circular Depressed Cladding Waveguides in Mechanically Robust, Biocompatible nc-YSZ Transparent Ceramics by fs Laser Pulses

• Published in: Journal of lightwave technology Vol. 37; no. 13; pp. 3119 - 3126
• Main Authors: Guerra-Olvera, Cecilia, Castillo, Gabriel R., Penilla, Elias H., Uahengo, Gottlieb, Garay, Javier E., Camacho-Lopez, Santiago
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.07.2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Biocompatibility; Biocompatible materials; Biomedical optical imaging; Ceramics; Cladding; cladding waveguides; Damage localization; Degree of crystallinity; Dependence; Femtosecond pulses; Fracture mechanics; laser materials processing; Lasers; Optical device fabrication; Optical properties; Optical pulses; Optical refraction; Optical waveguides; Photonics; Refractivity; Residual stress; transparent ceramics; Waveguide lasers; Waveguides; YSZ; Yttria-stabilized zirconia; Yttrium oxide; Zirconium dioxide
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2019.2911256

We report on the fabrication of depressed cladding waveguides inscribed by direct femtosecond laser pulses irradiation in transparent nc-yttria stabilized zirconia (YSZ) polycrystalline ceramics. The waveguides consisted of two different circular structures with diameters of 30 and 100 μm, and different lengths. Optical characterization at 633 and 1568 nm was performed. The obtained modal profiles show dependence on the structure and size of the waveguides. We estimate a laser-induced refractive index contrast of nearly 10 -2 , larger than can be explained by induced residual stresses alone. We conjecture that laser interactions lead to localized physical damage, i.e., microvoids cracks and possibly a decreased degree of crystallinity in the laser processed zones, which is supported by Raman measurements. Our results suggest a promising potential use of nc-YSZ in photonic bio-applications.