High-brightness diode lasers obtained via off-axis spectral beam combining with selective feedback

Area of Science:

• Optics and Photonics
• Laser Physics
• Materials Science

Background:

• High-power lasers are crucial for various applications.
• Improving beam quality and brightness is a key challenge in laser development.
• Current methods often face limitations in scalability and efficiency.

Purpose of the Study:

• To propose and demonstrate a modified off-axis spectral beam combining method.
• To enhance the beam quality and brightness of high-power laser systems.
• To achieve high output power with excellent beam characteristics.

Main Methods:

• Implemented a modified off-axis spectral beam combining technique.
• Utilized selective feedback with a high reflectivity mirror.
• Coupled optical modes within an external cavity.

Main Results:

• Demonstrated emission power exceeding 20 W.
• Achieved M² factors of 2.7 (fast axis) and 4.4 (slow axis).
• Improved system beam quality by a factor of three to four compared to single emitters.
• Attained a high brightness of 190 MW cm⁻² sr⁻¹.

Conclusions:

• The modified spectral beam combining method effectively enhances laser performance.
• Selective feedback is a viable strategy for improving laser beam quality and brightness.
• The demonstrated system offers a promising solution for high-power, high-brightness laser applications.