Recent Progresses on Hybrid Lithium Niobate External Cavity Semiconductor Lasers.

Area of Science:

• Photonics
• Materials Science
• Integrated Optics

Background:

• Thin film lithium niobate (TFLN) is a key material for large-scale photonic integrated circuits (PICs).
• On-chip, electrically tunable, narrow-linewidth lasers are crucial for applications like optical communication and LiDAR.
• Electrically driven, high-power, narrow-linewidth lasers on TFLN are an emerging research area.

Purpose of the Study:

• To review recent advancements in narrow-linewidth compact laser sources on TFLN platforms.
• To highlight the role of hybrid TFLN/III-V semiconductor integration techniques.
• To provide an alternative solution for high-performance on-chip lasers for TFLN PICs.

Main Methods:

• Review of compact external cavity semiconductor lasers (ECSLs).
• Analysis of TFLN photonic chips with various external cavity structures for on-chip optical feedback.
• Discussion of hybrid integration techniques for TFLN and III-V semiconductors.

Main Results:

• Demonstration of ECSLs based on TFLN photonic chips.
• Exploration of different photonic structures for constructing external cavities.
• Progress in hybrid TFLN/III-V integration for laser development.

Conclusions:

• Hybrid TFLN/III-V integration is a promising approach for on-chip narrow-linewidth lasers.
• These integrated lasers offer potential for future TFLN PICs and scientific applications.
• Further research is needed to develop high-power, electrically driven sources.