Self‐Injection Locked Frequency Conversion Laser

• Published in: Laser & photonics reviews Vol. 17; no. 5
• Main Authors: Ling, Jingwei, Staffa, Jeremy, Wang, Heming, Shen, Boqiang, Chang, Lin, Javid, Usman A., Wu, Lue, Yuan, Zhiquan, Lopez‐Rios, Raymond, Li, Mingxiao, He, Yang, Li, Bohan, Bowers, John E., Vahala, Kerry J., Lin, Qiang
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01-05-2023
• Subjects: Coherence; Emitters; Frequency locking; Harmonic generations; integrated photonics; Lasers; Lithium niobates; second harmonic generation; self‐injection locking; Thin films
• ISSN: 1863-8880; 1863-8899
• DOI: 10.1002/lpor.202200663

High‐coherence visible and near‐visible laser sources are centrally important to the operation of advanced position/navigation/timing systems as well as classical/quantum sensing systems. However, the complexity and size of these bench‐top lasers are an impediment to their transition beyond the laboratory. Here, a system‐on‐chip that emits high‐coherence near‐visible lightwaves is demonstrated. The devices rely upon a new approach wherein wavelength conversion and coherence increase by self‐injection locking are combined within a single nonlinear resonator. This simplified approach is demonstrated in a hybridly‐integrated device and provides a short‐term linewidth of around 4.7 kHz (10 kHz before filtering). On‐chip converted optical power over 2 mW is also obtained. Moreover, measurements show that heterogeneous integration can result in a conversion efficiency higher than 25% with an output power over 11 mW. Because the approach uses mature III–V pump lasers in combination with thin‐film lithium niobate, it can be scaled for low‐cost manufacturing of high‐coherence visible emitters. Also, the coherence generation process can be transferred to other frequency conversion processes, including optical parametric oscillation, sum/difference frequency generation, and third‐harmonic generation.
High‐coherence visible and near‐visible laser sources are centrally important to the operation of advanced position/navigation/timing systems as well as classical/quantum sensing systems. Here, a system‐on‐chip that emits high‐coherence near‐visible lightwaves is demonstrated. The devices rely upon a new approach wherein wavelength conversion and coherence increase by self‐injection locking are combined within a single nonlinear resonator.