Randomly phase-locked microlaser arrays and fuzzy eigenmodes with stochastic phasing

Deviations in the cold cavity parameters, random or systematic, produce incoherently phased-locked laser arrays with unevenly distributed phase difference and intensity. The collective radiation fields constitute "fuzzy" eigenmodes; the phasing among cavities is constant in time but changes randomly from site-to-site. The existence and structure of such eigenmodes is demonstrated numerically and analyzed theoretically using the rate equations for coupled semiconductor laser cavities. Active coupling, whereby one cavity's radiation field modulates the complex gain of nearby cavities (cross-cavity hole burning), is essential for the frequency pulling allowing synchronization of the laser operating frequencies.