Copper-Free Photonic Circuits Enable Breakthrough in Chip-Scale Frequency Comb Generation
Scientists have identified and eliminated copper contamination as the primary thermal absorption source in silicon nitride photonic circuits. This breakthrough enables deterministic generation of dissipative Kerr solitons, overcoming a major hurdle in chip-scale optical frequency comb technology.
Copper Contamination Identified as Key Thermal Challenge
Researchers have made a significant breakthrough in integrated photonics by identifying copper impurities as the primary source of thermal absorption in silicon nitride photonic integrated circuits (PICs), according to a recent study published in Nature. Sources indicate that these impurities, previously undetected in electronic-grade silicon wafers, were found to diffuse into the silicon nitride layer during high-temperature annealing processes and become trapped, creating thermal effects that have hampered deterministic soliton generation.