Field Demonstration of Multi-Wavelength Optical Transmission with Microresonator Frequency Combs

Data traffic has been increasing with the spread of the internet. Therefore, a network that connects data centers and metropolitan areas requires a high-capacity, low-latency, and low-power-consumption optical communication system [1]. Since microresonator-based optical frequency combs (i.e., microcombs) have many longitudinal modes, they are expected to be applied to wavelength division multiplexing (WDM) communications [2], [3]. We describe a field demonstration of a multi-wavelength optical transmission with a soliton microcomb. We employed intensity modulation and direct detection (IM-DD) for a simple and low-latency communication system [3]. We also used a magnesium fluoride (MgF2) microresonator because it has a small free spectral range (FSR) for efficient bandwidth use. Although sophisticated experiments have already been reported in the laboratory, we believe that our demonstration using a commercially installed optical fiber in a metropolitan area is a significant step towards the practical use of a microresonator system.