Grating-assisted add-drop multiplexer realized in silica-on-silicon technology
2003 (English)In: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, Vol. 4941, 43-50 p.Article in journal (Refereed) Published
Silica-on-Silicon is a well established technology for the fabrication of low insertion loss planar lightwave circuits. The Ge-doped waveguide core material, deposited with low temperature plasma enhanced chemical vapor deposition and not subjected to high temperature annealing, is highly UV light photosensitive, due to residual Ge/Si-OH groups in the material that, similarly to hydrogen loading, can contribute to the formation of those defect centers responsible for the photosensitivity. Gratings have been-fabricated using a pulsed 193 nm ArF excimer laser and a phase mask. 25 mm long gratings, written on standard straight waveguides, show a record 47 dB extinction ratio and 0.2 nm rejection bandwidth for TE polarization, without hydrogen loading. Such narrow linewidth filters could find application in dense WDM systems. We designed and fabricated a compact Add/Drop multiplexer based on a high bandwidth, 2x2 multimode interference device, having a Bragg grating written in the multi-mode region. The characterisation for the TE polarisation prove the proposed Add/Drop principle, showing, in correspondence of the dropped channel, a 30dB dip at the transmitted output and a reflection peak at the drop output, this last having a larger bandwidth, and around 3dB excess loss respect to the transmitted channels.
Place, publisher, year, edition, pages
2003. Vol. 4941, 43-50 p.
add-drop multiplexing, Bragg grating, multimode interference (MMI), silica-on-silicon technology, planar lightwave circuit (PLC)
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-4996DOI: 10.1117/12.468509ISI: 000182689900005OAI: oai:DiVA.org:kth-4996DiVA: diva2:7373
QC 201010042005-03-102005-03-102010-10-04Bibliographically approved