Design, fabrication, and characterization of deep-etched waveguide gratings

Kleckner, T.C., Modotto, D., Locatelli, A., Mondia, J.P., Linden, S., Morandotti, R., De Angelis, C., Stanley, C.R., van Driel, H.M. and Aitchison, J.S. (2005) Design, fabrication, and characterization of deep-etched waveguide gratings. Lightwave Technology, 23(11), pp. 3832-3842. (doi: 10.1109/JLT.2005.857737)

Abstract

One-dimensional (1-D) deep-etched gratings on a specially grown AlGaAs wafer were designed and fabricated. The gratings were fabricated using state-of-the-art electron beam lithography and high-aspect-ratio reactive ion etching (RIE) in order to achieve the required narrow deep air slots with good accuracy and reproducibility. Since remarkable etch depths (up to 1.5 /spl mu/m), which completely cut through the waveguide core layer, have been attained, gratings composed of only five periods (and, thus, shorter than 6 /spl mu/m) have a bandgap larger than 100 nm. A defect was introduced by increasing the width of the central semiconductor tooth to create microcavities that exhibit a narrow transmission peak (less than 7 nm) around the wavelength of 1530 nm. The transmission spectra between 1460 and 1580 nm have been systematically measured, and the losses have been estimated for a set of gratings, both with and without a defect, for different periods and air slot dimensions. Numerical results obtained via a bidirectional beam propagation code allowed the evaluation of transmissivity, reflectivity, and diffraction losses. By comparing experimental results with the authors' numerical findings, a clear picture of the role of the grating's geometric parameters in determining its spectral features and diffractive losses is illustrated.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Stanley, Professor Colin
• Authors: Kleckner, T.C., Modotto, D., Locatelli, A., Mondia, J.P., Linden, S., Morandotti, R., De Angelis, C., Stanley, C.R., van Driel, H.M., and Aitchison, J.S.
• Subjects: T Technology > TK Electrical engineering. Electronics Nuclear engineering
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering; University Centres > Glasgow Materials Research Initiative
• Journal Name: Lightwave Technology
• Publisher: Institute of Electrical and Electronics Engineers
• ISSN: 0733-8724
• Copyright Holders: Copyright © 2005 Institute of Electrical and Electronics Engineers
• First Published: First published in Lightwave Technology 23(11):3832-3842
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher