Collective oscillations, coherent phase locking and applications to beam steering in periodic interacting VCSEL arrays

Summary form only given. Periodic arrangements of VCSEL micro-cavities separated by distances comparable to the 1/e/sup 2/ transverse length of the cavity mode intensity interact though their fringe fields. Such interactions include cross-polarization, cross-gain and cross hole burning among nearest neighbor cavities. Since each VCSEL possesses a cavity oscillation frequency the cavity array constitutes a coupled oscillator lattice admitting collective oscillation modes. Analytic derivation of the cross-coupling terms and subsequent integration of the resulting coupled rate equations, describing the dynamics of 1-D or 2-D periodic arrays of identical cavities, demonstrate that, under constant drive current and for random initial conditions, the arrays settle to a phase-locked steady state, with the same fixed phase difference /spl Delta//spl phi/ between any two neighbors. Perturbations about the steady-state propagate as collective oscillations (Bloch type modulation waves) over the array and are characterized by a given dispersion relation. A method of controlling the phase difference /spl Delta//spl phi/ is proposed, appropriate for achieving Bragg condition and beam steering, by imposing a priming current of appropriate frequency on top of the main bias current.