Phase locked vertical cavity surface emitting laser

A VCSEL amplifier has been phase locked to a master oscillator laser. The central frequency of the light may be slightly shifted, but by an amount which is significantly less than the linewidth of the signal. The coherence of the amplified light is not significantly degraded by frequency broadening or noise. These results suggest that a MOPA phased array using VCSEL amplifiers is feasible. Experiments to demonstrate a coherent 1x2 array with discrete VCSELs are at present ongoing.