Compact and low-loss interleave filter employing lattice-form structure and silica-based waveguide

• Published in: Journal of lightwave technology 2004-03, Vol.22 (3), p.895-902
• Main Authors: Oguma, M., Kitoh, T., Inoue, Y., Mizuno, T., Shibata, T., Kohtoku, M., Hibino, Y.
• Format: Article
• Language: English
• Subjects: Applied sciences; Bandwidth; Bandwidths; Channel spacing; Channels; Circuit properties; Demultiplexing; Design optimization; Dispersion; Dispersions; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Fabrication; Filters; Insertion loss; Integrated optics. Optical fibers and wave guides; Lattices; Noise levels; Optical and optoelectronic circuits; Polarization; Ripples; Tolerances; Waveguides; Wavelengths
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2004.824544

This paper describes a compact and practical interleave filter with uniform multi/demultiplexing properties and a wide operational wavelength range realized by using a lattice-form structure and a silica-based waveguide. In the design, we optimized the bandwidth by controlling the lattice stage number and the loss ripple in the spectrum. Moreover, we propose a novel coupler with a large fabrication tolerance, a new tandem configuration that provides uniform characteristics and low dispersion, a polarization dependence compensation method, and a folded configuration, which are effective in realizing a high-performance interleave filter. Based on the above techniques, we fabricated a 50-GHz channel spacing interleave filter by using planar-lightwave-circuit technologies and demonstrated that it performed well throughout the C-band, exhibiting a low insertion loss of about 2 dB, a low chromatic dispersion of within +/-20 ps/nm, a 1-dB passband width of over 34 GHz, and a 30-dB stopband width of over 25 GHz, which are sufficient for a 10-Gbps transmission system.