Width Dependence of Inherent TM-Mode Lateral Leakage Loss in Silicon-On-Insulator Ridge Waveguides

• Published in: IEEE photonics technology letters Vol. 19; no. 6; pp. 429 - 431
• Main Authors: Webster, M.A., Pafchek, R.M., Mitchell, A., Koch, T.L.
• Format: Journal Article
• Language: English
• Published: New York IEEE 15.03.2007; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Confinement; Design engineering; Displays; Frequency conversion; Geometrical optics; Leakage; Leaky waves; Optical losses; Optical modulation; Optical refraction; Optical waveguides; Photonics; Ridges; Silicon; Silicon on insulator technology; silicon-on-insulator (SOI) technology; Slabs; Tellurium; Waveguides
• ISSN: 1041-1135; 1941-0174
• DOI: 10.1109/LPT.2007.891979

We report the first experimental observation in the optical domain of a dramatic width-dependent lateral leakage loss behavior for the TM-like mode of tight vertical confinement ridge waveguides formed in silicon-on-insulator. The lateral leakage loss displays a series of sharp cyclic minima at precise waveguide widths, and appears to be inherent to waveguide geometries of central importance to a wide variety of active devices in silicon photonics requiring lateral electrical access. This behavior is not predicted by the often-used effective-index-based methods, but is understood phenomenologically and also compared to prior numerical analysis and predictions of leaky mode behavior. It is shown that TM-like mode operation, critical to the operation of some active component designs, will require precision control of waveguide dimensions to achieve high performance