FABRICATION OF WAVEGUIDE-TYPE ADD/DROP GRATING FILTER BY RADIO-FREQUENCY MAGNETRON SPUTTERING TO INSERT GeO2-SiO2 CLADDING LAYERS

• Published in: Jpn.J.Appl.Phys ,Part 2. Vol. 42, no. 3B, pp. L307-L309. 2003 Vol. 42; no. 3B; pp. L307 - L309
• Main Authors: Ohkubo, H, Sato, S, Hongo, A, Kashimura, S, Uetsuka, H, Okano, H
• Format: Journal Article
• Language: English
• Published: 15-03-2003
• ISSN: 0021-4922
• DOI: 10.1143/jjap.42.L307

Authors developed a waveguide-type add/drop grating filter that has GeO2-SiO2 cladding layers inserted into the conventional waveguide structure by rf-magnetron sputtering to suppress cladding mode coupling loss. Optimizing the fabrication conditions for the GeO2-SiO2 core and cladding layers enabled authors to fabricate a waveguide-type add/drop grating with low loss and without voids in the narrow core-to-core gaps. Results showed that this waveguide, having high quality GeO2-SiO2 films and a unique structure, had a propagation loss of 0.18 dB/cm and suppressed the cladding mode coupling loss around 1550 nm to approximately 0.3 dB, compared with the 5.0 dB loss of conventional waveguides. 9 refs.