Ultra-high-speed MQW electroabsorption modulators with integrated waveguides

The input and output waveguides are integrated with a multiple-quantum-well (MQW) electroabsorption (EA) modulator to achieve ultra-high-speed modulation. This MQW-EA modulator with integrated waveguides has a larger modulation bandwidth due to a shorter modulation region, while maintaining a device length long enough for fabrication and packaging. An optimized device had a large modulation bandwidth of 50 GHz, a low driving voltage of less than 3 V, and a low fiber-to-fiber insertion loss of 8 dB, which are enough for 40-Gbit/s modulation. The advantage of packaging the modulator with integrated waveguides is also demonstrated: an assembled prototype module showed a large modulation bandwidth of more than 40 GHz. These results demonstrate that the MQW-EA modulator with integrated waveguides is advantageous in terms of ultra-high-speed operation as well as packaging.