Cheng Rebecca, Ren Xinyi, Reimer Christian, Yeh Matthew, Rosborough Victoria, Musolf Juergen, Johansson Leif, Zhang Mian, Yu Mengjie, Lončar Marko
Opt Lett. 2024 Jun 15;49(12):3504-3507. doi: 10.1364/OL.527659.
Stable pulse and flat-top frequency comb generation are an indispensable component of many photonic applications, from ranging to communications. Lithium niobate on insulator is an excellent electro-optic (EO) platform, exhibiting high modulation efficiency and low optical loss, making it a fitting candidate for pulse generation through electro-optic modulation of continuous-wave (CW) light, a commonly utilized method for generating ultrashort pulses. Here, we demonstrate an on-chip electro-optic comb generation module on thin-film lithium niobate (TFLN) consisting of a Mach-Zehnder interferometer (MZI) amplitude modulator (AM) and a cascaded phase modulator (PM) system driven by a single-electrode drive. We show that when operated in the correct regime, the lithium niobate chips can generate frequency combs with excellent spectral power flatness. In addition, we optically package one of the pulse generator chips via photonic wire bonding. The pulses generated by the photonic-wire-bonded device are compressed to 840 fs pulse duration using an optical fiber and show extremely stable operation.
稳定脉冲和平顶频率梳的产生是许多光子应用中不可或缺的组成部分，从测距到通信。绝缘体上铌酸锂是一种出色的电光（EO）平台，具有高调制效率和低光学损耗，使其成为通过对连续波（CW）光进行电光调制来产生脉冲的合适候选材料，这是一种常用的产生超短脉冲的方法。在此，我们展示了一种基于薄膜铌酸锂（TFLN）的片上电光梳产生模块，它由马赫曾德尔干涉仪（MZI）幅度调制器（AM）和由单电极驱动的级联相位调制器（PM）系统组成。我们表明，当在正确的工作模式下运行时，铌酸锂芯片可以产生具有出色光谱功率平坦度的频率梳。此外，我们通过光子线键合对其中一个脉冲发生器芯片进行光学封装。通过光子线键合器件产生的脉冲使用光纤压缩至840 fs的脉冲持续时间，并显示出极其稳定的运行状态。
