Science Daily April 20, 2020
Soliton microcombs can now be built using CMOS-compatible photonic integrated circuits. However, they operate with repetition rates significantly beyond those that conventional electronics can detect, preventing their use in microwave photonics. Researchers in Switzerland have demonstrated soliton microcombs operating in two widely employed microwave bands, the X-band (~10 GHz, for radar) and the K-band (~20 GHz, for 5G). Driven by a low noise fibre laser, these devices produce more than 300 frequency lines within the 3 dB bandwidth, and generate microwave signals with phase noise levels comparable to modern electronic microwave oscillators. The results establish integrated microcombs as viable low-noise microwave generators and the low soliton repetition rates could reduce the system complexity of soliton-based integrated frequency synthesizers and atomic clocks…read more. TECHNICAL ARTICLE