December 16, 2009 Wednesday 15:30
Mehmet E. Solmaz , Texas A&M University
Chalcogenide waveguides vertically integrated on lithium-niobate

Chalcogenide (arsenic-trisulfide, As2S3) waveguides vertically integrated on titanium diffused lithium-niobate (Ti:LiNbO3) expands the possibilities in the field of chip-scale optics. Due to its very low core-to-cladding index ratio, and very large mode size Ti:LiNbO3 waveguides are not suitable for making optical waveguides with small bend radii. A higher index material, As2S3 is introduced on Ti:LiNbO3 as a waveguide to enable structures such as ring resonators, u-bends, and tight s-bends [1]. Due to its high core-to-cladding index ratio, As2S3 waveguides allow bending structures as low as 290 m in diameter [2]. Further modifications to waveguide and taper design can bring the radius down to less than 50 m. Using the electro-optic effect, and integrability of Ti:LiNbO3 waveguides with regular single-mode fiber and the ability of As2S3 to create small bend radii structures together allows us to realize even more functionality on the same optical chip. This seminar will explore the first demonstration of As2S3 s-bends and ring resonators vertically fabricated on a well-established optical waveguide material. Research on the design, and fabrication development of As2S3-on-Ti:LiNbO3 optical waveguides are done as a part of doctoral degree requirement.

[1] M. E. Solmaz, D. B. Adams, S. Grover, W. C. Tan, X. Xia, O. Eknoyan, and C. K. Madsen, "Compact Bends for Achieving Higher Integration Densities for LiNbO3 Waveguides," Photonics Technology Letters, IEEE, vol. 21, pp. 557-559, 2009.
[2] M. E. Solmaz, D. B. Adams, W. C. Tan, W. T. Snider, and C. K. Madsen, "Vertically integrated As2S3 ring resonator on LiNbO3," Opt. Lett., vol. 34, pp. 1735-1737, 2009.