Fabrication of a two-dimensional phased array of vertical-cavity surface-emitting lasers

Abstract
We report the successful fabrication of a two-dimensional phase-locked array of vertical-cavity surface-emitting lasers. The array was comprised of more than 160 vertical-cavity surface-emitting lasers of 1.3 μm diameter with a separation of less than 0.1 μm between each lasing element. The array had a 25 μm diameter and each of the elemental lasers was located on a two-dimensional rectangular lattice. The threshold current of the two-dimensional array 45 mA yields a threshold current of 280 μA for an elemental laser. The far-field beam angle of the array was as narrow as 7°, and the spectral purity was found to be good enough to allow for a clear holographic image reconstruction of a holographic memory.