Fujitsu Laboratories Ltd. and Heinrich Hertz Institut (HHI) announced the development of an ultra high-speed optical switch that uses nonlinear optical fiber to reduce optical amplitude noise, which degrades the quality of optical signals when they are transmitted. Employing this technology, suppression of optical amplitude noise using a 107 gigabit per second (Gbps) phase modulated ultra high-speed signal was successfully verified. In addition, in a data transmission test across 320 km, it was verified that data quality after transmission could be received with roughly the equivalent of its quality prior to transmission.
The new technology developed by Fujitsu and HHI employs an ultra high-speed optical switch they developed that is capable of processing optical signals in less than a picosecond. By controlling the power gain of the optical parametric amplification effect from the optical signals, raising it when signals are weak and lowering it when signals are strong, the switch reduces optical noise without the need to convert optical signals into electrical signals.
By placing an ultra high-speed optical switch employing this technology in the middle of an optical transmission link, even after data was transmitted across 320 kilometers with a 107Gbps optical signal modulated by differential phase shift keying(DPSK) data, the transmitted data essentially reproduced without change the characteristics of the data prior to transmission, thereby verifying high-quality optical transmission through this test. Compared to results when the switch is not employed, it was also verified that using the switch makes it possible to roughly double the length of transmission distances.
In addition, by optimizing the design of the nonlinear optical fiber, it is possible to cover much wider wavelength ranges than are currently used in optical transmissions, and handle optical signals in a variety of modulation formats. It is anticipated that this new technology can be applied to optical regeneration, which is a key technology for next-generation ultra high-speed photonic networks.