High-brightness scalable continuous-wave single-mode photonic-crystal laser

Area of Science:

• Photonics and Laser Physics
• Semiconductor Lasers

Background:

• High-power semiconductor lasers traditionally suffer from poor beam quality and thermal instability during continuous-wave (CW) operation.
• Achieving single-mode, high-power, and high-beam-quality semiconductor lasers is a key goal, aiming to rival or replace conventional bulky lasers.

Purpose of the Study:

• To overcome limitations of conventional high-power semiconductor lasers.
• To develop large-scale photonic-crystal surface-emitting lasers (PCSELs) with improved beam quality and stable CW operation.

Main Methods:

• Engineered controlled Hermitian and non-Hermitian couplings within the photonic crystal structure.
• Incorporated a pre-installed spatial distribution of the lattice constant to maintain couplings under CW conditions.
• Utilized large-scale PCSELs with a 3mm resonant diameter.

Main Results:

• Achieved continuous-wave (CW) output power exceeding 50W.
• Demonstrated purely single-mode oscillation with a narrow beam divergence of 0.05°.
• Reached a brightness of 1 GW cm⁻² sr⁻¹, comparable to bulky lasers.

Conclusions:

• The developed PCSELs surmount challenges of poor beam quality and thermal instability in high-power semiconductor lasers.
• This work represents a significant milestone towards 1-kW-class single-mode semiconductor lasers.
• These advanced PCSELs are poised to replace conventional, bulkier laser systems in various applications.