Highly Reliable, Ultra‐Wideband 100 GHz Quantum‐Dot Mode‐Locked Frequency Combs for O‐Band Terabit Optical Interconnects

Abstract Quantum dot (QD) mode‐locked laser‐based optical frequency combs (OFCs) are emerging as a critical solution for achieving low‐cost, high‐efficiency, and large‐capacity optical interconnects. The practical implementation of wavelength division multiplexing interconnects requires an OFC source that operates at high, stabilized temperature with a minimum 100 GHz channel spacing to enable high‐bandwidth modulation while mitigating the complexity of optical filtering and detection. By leveraging the advanced co‐doping technique and a colliding pulse mode‐locking scheme, here, a compact, ultra‐wideband, highly reliable 100 GHz‐spacing InAs/GaAs QD OFC source operating up to a record temperature of 140 °C is reported. The comb source delivers a record 3 dB optical bandwidth of 14.312 nm, containing 26 flat‐top comb lines, each supporting 128 Gb s −1 PAM‐4 modulation, resulting in a total throughput of 3.328 Tb s −1 at an ultra‐low power consumption of 0.394 pJ bit −1 at 25 °C. Performance remains stable at 85 °C, with negligible degradation of device critical metrics. Remarkably, accelerated aging tests (85 °C with 8× threshold current injection) predicted a mean time to failure of ≈207 years. The QD OFC source demonstrated in this work, for the first time, establishes a concrete link between fundamental research on comb sources and their practical deployment in next‐generation, high‐density optical interconnects.