Abstract

The rapid and global spread of the Internet has accelerated the need to reduce the cost of optical communication networks based on wavelength division multiplexing (WDM) systems. Multi-wavelength light sources^1,2 are attractive for such low-cost WDM systems. We have been developing a compact multi-wavelength light source by integrating external cavity lasers (ECLs) with planar lightwave circuits (PLCs) on a Si substrate.An ECL^3,4 is composed of a UV written waveguide grating and an LD mounted on a PLC platform. Compared with other types of lasers, the PLC-type ECL has the advantages of a stable oscillation wavelength fixed to the Bragg wavelength, only slight wavelength temperature dependence (about 0.01 nm/°C) and the capacity for high-density integration. We used these advantages to demonstrate 2 nm spacing, 4-channel single mode oscillation with a 2.5 Gb/s direct modulation.⁵

© 2002 Optical Society of America