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Abstract Optical microcomb underpins a wide range of applications from communication, metrology, to sensing. Although extensively explored in recent years, challenges remain in key aspects of microcomb such as complex soliton initialization, low power efficiency, and limited comb reconfigurability. Here we present an on-chip microcomb laser to address these key challenges. Realized with integration between III and V gain chip and a thin-film lithium niobate (TFLN) photonic integrated circuit (PIC), the laser directly emits mode-locked microcomb on demand with robust turnkey operation inherently built in, with individual comb linewidth down to 600 Hz, whole-comb frequency tuning rate exceeding 2.4 × 1017 Hz/s, and 100% utilization of optical power fully contributing to comb generation. The demonstrated approach unifies architecture and operation simplicity, electro-optic reconfigurability, high-speed tunability, and multifunctional capability enabled by TFLN PIC, opening up a great avenue towards on-demand generation of mode-locked microcomb that is of great potential for broad applications.
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This content will become publicly available on July 26, 2026
Narrow linewidth on-chip III-V/TFLT laser
We report a narrow-linewidth laser based on thin-film lithium tantalate (TFLT). The laser is composed of an InP reflective semiconductor optical amplifier gain chip hybrid integrated with a TFLT waveguide external cavity cladded with a silicon oxide extended Bragg grating. The single-frequency laser device achieves an on-chip output power of approximately 26 mW and an intrinsic Lorentzian linewidth of ~94 Hz. These results highlight the great potential of TFLT for integrated photonic laser applications, enabling high-coherence and high-power laser sources in a compact platform.
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- Award ID(s):
- 2329017
- PAR ID:
- 10618541
- Publisher / Repository:
- Optical Society of America
- Date Published:
- Journal Name:
- Optics Letters
- Volume:
- 50
- Issue:
- 15
- ISSN:
- 0146-9592; OPLEDP
- Format(s):
- Medium: X Size: Article No. 4754
- Size(s):
- Article No. 4754
- Sponsoring Org:
- National Science Foundation
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