FABRICATION AND CHARACTERIZATION OF NON-DOPED SiO2 CLADDING LAYER FOR POLARIZATION-INSENSITIVE SILICA WAVEGUIDE BY USING PLASMA ENHANCED CHEMICAL VAPOR DEPOSITION

• Published in: Jpn.J.Appl.Phys ,Part 1. Vol. 42, no. 7A, pp. 4340-4344. 2003 Vol. 42; no. 7A; pp. 4340 - 4344
• Main Authors: Ohkubo, H, Hongo, A, Kashimura, S, Ohkawa, M, Ohira, K, Uetsuka, H, Okano, H
• Format: Journal Article
• Language: English
• Published: 2003
• ISSN: 0021-4922
• DOI: 10.1143/jjap.42.4340

Authors developed a technique for fabricating the cladding layers of SiO2 waveguides and used this technique to fabricate an arrayed waveguide grating (AWG). The technique consists of two deposition process of non-doped SiO2. The first deposition process is a two-step deposition process combining PECVD using tetraethylorthosilicate (TEOS) gas with an etching-back non-doped SiO2 by RF sputtering, and the second is a deposition process by means of PECVD using SiH4 gas. The non-doped SiO2 cladding layer must meet requirements of a thickness over 10 mu m without cracking and a refractive index the same as that of fused SiO2. By using this fabrication technique, these requirements are satisfied and narrow core-to-core gaps are filled with non-doped SiO2 without producing voids. The developed SiO2 waveguide with non-doped SiO2 cladding has a propagation loss of 0.07 dB/cm and the developed AWG has a polarization sensitivity of 0.001 nm, which is one order of magnitude lower than that of existing AWGs. 12 refs.