With the huge growth in traffic on the Internet from simple text data to high quality voice, images, and real-time video, it has become increasingly important to realize a high-capacity and high-speed network to support the daily needs of modern communications. Ultrahigh-speed optical communication is the key technology for building such an interconnected world. This new laboratory aims to achieve a global ultrahigh-speed optical network in the 21 century by engaging in research on ultrashort pulse generation and transmission. Our research areas include optical solitons, high-speed mode-locked lasers, optical signal processing, and the development of fibers with new functions.

For soliton transmission, we have shown that the adoption of dispersion management in an optical fiber transmission line enables us to increase greatly the dispersion tolerance and power margin of a soliton system by comparison with conventional systems. In the next phase of this work, it is important to increase the bit rate of a single channel to above 100 Gbit/s and to apply solitons to high-speed optical signal processing.

We are also actively engaged in work on femtosecond pulse generation and its application to ultrahigh-speed optical time division multiplexed (OTDM) transmission. We recently succeeded in a 1.28 Tbit/s OTDM transmission over 70 km by combining a new type of 10 GHz mode-locked fiber laser and an optical soliton pulse compression technique. In addition, we are developing a new frequency standard by stabilizing the mode-locked laser so that it has a highly controlled longitudinal mode separation. This technique is also applicable to the microwave-photonics field. Another important area of our research is in the development of photonic crystal fibers. These special fibers have many air holes in their cross-section, and have potential applications to new optical communication systems operating in the currently unused 500-1000 nm band.

Research topics:

1. Ultrahigh-speed optical soliton transmission and nonlinear optics in optical fibers

2. Terabit/s OTDM transmission using femtosecond pulse train

3. Ultrashort mode-locked lasers and their application to frequency standards and microwave photonics

4. Photonic crystal fibers and optical fibers with new functionality