Interferometric phase shift compensation technique for high-power, tiled-aperture coherent beam combination.

We propose a simple coherent beam combining technique for applications in high-power multichannel laser amplifier systems with tiled aperture design. Using a photodiode pair coupled with piezo-actuator mirrors, we demonstrated robust beam combining bandwidth (~1 KHz) and root mean-square deviation (~λ/25) for two beam channels. We estimate that the performance of this technique can be further enhanced in terms of operational bandwidth and phase locking accuracy. It is not limited by single beam power or channel number restrictions, does not require optical phase retrieval algorithms, or calibrations, and can be integrated into various master oscillator power amplifier architectures.