0.5-μm InP HBTによる光通信用60-GS/s D/A変換器

摘要

100 Gb/s/chを超える高速・大容量光通信システムに向けて，16-QAMや64-QAMといった高度な多値変調技術の適用が検討されている.特に光送信器側では，高度な変調信号を生成するために超高速で動作するD/A変換器が求められる.今回我々は，そのような将来の光通信システムに向けて，0.5-μm InP HBTを用い60 GS/sで動作可能な超高速D/A変換器を実現した.本D/A変換器の利用により，最大60GS/s（60Gbaud）での多レベル変調信号の生成が可能となり，400Gb/s/ch級の16-QAM伝送などの実現が期待できる.%High-order multi-level modulation formats, such as 16-QAM and 64-QAM, are promising techniques for constructing beyond- 100-Gb/s/ch optical communication systems. In the transmitter for such systems, ultrahigh-speed digital-to-analog converters (DACs) are key components for generating complex modulated signals. We have developed a 60-GS/s ultrahigh-speed DAC with 0.5-um InP HBT technology for such systems. The fabricated DAC can provide clear multi-level signals for QAM transmission at a sampling rate of up to 60 GS/s. This DAC can be applied to 400-Gb/s/ch-class multi-level optical transmission systems.