Coherent beam combining of fiber lasers using a CDMA-based single-frequency dithering technique

Area of Science:

• Optics and Photonics
• Laser Physics
• Signal Processing

Background:

• High-power and high-brightness laser output is crucial for various applications.
• Coherent beam combination (CBC) is a key technology for achieving advanced laser performance.
• Existing single-frequency dithering techniques face limitations in speed and channel scalability.

Purpose of the Study:

• To develop a novel single-frequency dithering technique for CBC systems.
• To enhance the phase control speed and increase the number of channels in CBC.
• To demonstrate the feasibility of the proposed technique through simulations and experiments.

Main Methods:

• Implementation of a code division multiple access (CDMA) based dithering technique.
• Design and application of orthogonal phase control signals.
• Experimental validation of phase locking for multiple channels using the developed signals.

Main Results:

• Successful phase locking of five channels was achieved.
• The residual phase error in the closed-loop system was maintained below λ/30.
• The phase control speed of the CBC system was enhanced by nearly eleven times compared to traditional methods.

Conclusions:

• The proposed CDMA-based dithering technique offers a significant improvement in CBC performance.
• Orthogonal phase control signals effectively increase channel capacity and control speed.
• This advancement paves the way for more efficient high-power laser systems.