Synchronization of chaotic oscillations generated in two $\mathrm{Nd}:{\mathrm{YVO}}_4$ microchip lasers is experimentally and numerically demonstrated with master-slave coupling schemes. The synchronization performance under some parameter mismatch between the two lasers is quantitatively characterized. Synchronization is always achieved when the lasing frequency of the slave laser is matched to that of the master laser through injection locking. Accurate synchronization of chaos at an average intensity error of less than 2% is attained and maintained for tens of hours. The modulation parameters of the two lasers do not need to be matched for synchronization when the injection power is at a sufficiently high level, because chaos synchronization is based on its injection-locking performance. For accurate synchronization in multimode lasers, the power distribution among longitudinal modes needs to be matched.

• Received 1 December 1999

DOI:https://doi.org/10.1103/PhysRevE.62.1960