Observation and analysis of phase-locking in parabolic bow-tie laser arrays

This paper presents experimental and theoretical results to show that in-phase coherent coupling occurs in high-power arrays of parabolic bow-tie lasers. Such devices require simple and inexpensive device fabrication, thus providing a cost-effective highpower laser for high-brightness operation at 980 nm. The maximum brightness achieved was 318MW cm-2sr-1 at 20 times the threshold with far-field full-width at half-maximum less than 1.5 times the diffraction limit, measured without the use of external lenses under low-duty cycle (0.1%) pulsed operation. Results obtained from double-slit interference experiments show a clear distinction between phase-coherent arrays and corresponding arrays of independent emitters.