Piezoelectrically tunable, narrow linewidth photonic integrated extended-DBR lasers

作者：Anat Siddharth, Alaina Attanasio, Simone Bianconi, Grigory Lihachev, Junyin Zhang, Zheru Qiu, Andrea Bancora, Scott Kenning, Rui Ning Wang, Andrey Voloshin, Sunil A. Bhave, Johann Riemensberger, Tobias J. Kippenberg · 发表于：Optica · 年份：2024 · DOI：10.1364/optica.524703 · 被引用次数：52 · 研究领域：Advanced Fiber Laser Technologies、Photonic and Optical Devices、Advanced Fiber Optic Sensors

Recent advancements in ultra-low-loss silicon nitride (Si 3 N 4 )-based photonic integrated circuits have surpassed fiber lasers in coherence and frequency agility. However, high manufacturing costs of DFB and precise control requirements, as required for self-injection locking, hinder widespread adoption. Reflective semiconductor optical amplifiers (RSOAs) provide a cost-effective alternative solution but have not yet achieved similar performance in coherence or frequency agility, as required for frequency modulated continuous wave (FMCW) LiDAR, laser locking in frequency metrology, or wavelength modulation spectroscopy for gas sensing. Here, we overcome this challenge and demonstrate an RSOA-based and frequency-agile fully hybrid integrated extended distributed Bragg reflector (E-DBR) laser with high-speed tuning, good linearity, high optical output power, and turn-key operability. It outperforms Vernier and self-injection locked lasers, which require up to five precise operating parameters and have limitations in continuous tuning and actuation bandwidth. We maintain a small footprint by utilizing an ultra-low-loss 200 nm thin Si 3 N 4 platform with monolithically integrated piezoelectric actuators. We co-integrate the DBR with a compact ultra-low-loss spiral resonator to further reduce the intrinsic optical linewidth of the laser to the Hertz-level—on par with the noise of a fiber laser—via self-injection locking. The photonic integrated E-DBR lasers operate at 1550 nm an...