A quantum dot (QD) mode-locked laser as an active comb generator takes advantage of its small footprint, low power consumption, large optical bandwidth, and high-temperature stability, which is an ideal multi-wavelength source for applications such as datacom, optical interconnects, and LIDAR. In this work, we report a fourth-order colliding pulse mode-locked laser (CPML) based on InAs/GaAs QD gain structure, which can generate ultra-stable optical frequency combs in the O-band with 100 GHz spacing at operation temperature up to 100°C. A record-high flat-top optical comb is achieved with 3 dB optical bandwidth of 11.5 nm (20 comb lines) at 25°C. The average optical linewidth of comb lines is measured as 440 kHz. Single-channel non-return-to-zero modulation rates of 70 Gbit/s and four-level pulse amplitude modulation of 40 GBaud/s are also demonstrated. To further extend the comb bandwidth, an array of QD-CPMLs driven at separate temperatures is proposed to achieve 36 nm optical bandwidth (containing 60 comb lines with 100 GHz mode spacing), capable of a total transmission capacity of 4.8 Tbit/s. The demonstrated results show the feasibility of using the QD-CPML as a desirable broadband comb source to build future large-bandwidth and power-efficient optical interconnects.

中文翻译：

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超宽带平顶量子点梳状激光器

量子点 (QD) 锁模激光器作为有源梳状发生器，具有占用空间小、功耗低、光带宽大和高温稳定性等优点，是数据通信等应用的理想多波长光源，光互连和激光雷达。在这项工作中，我们报告了一种基于 InAs/GaAs QD 增益结构的四阶碰撞脉冲锁模激光器 (CPML)，它可以在工作温度高达 100 GHz 的 O 波段产生超稳定的光学频率梳。至 100°C。在 25°C 时，以 11.5 nm（20 条梳状线）的 3 dB 光学带宽实现了创纪录的平顶光梳。梳状线的平均光学线宽测量为 440 kHz。还演示了 70 Gbit/s 的单通道不归零调制速率和 40 GBaud/s 的四级脉冲幅度调制。为了进一步扩展梳状带宽，提出了在不同温度下驱动的 QD-CPML 阵列，以实现 36 nm 的光带宽（包含 60 条梳状线，模式间隔为 100 GHz），总传输容量为 4.8 Tbit/s。展示的结果表明，使用 QD-CPML 作为理想的宽带梳状光源来构建未来的大带宽和高能效光互连是可行的。