Noise reduction in spatially coupled microchip lasers

Noise reduction effects in two spatially coupled Nd:YVO4 microchip lasers are studied theoretically in the case of similar intensity pump beams. We demonstrate that the synchronization phenomena commonly observed in spatially coupled unstable lasers applies to the quantum-noise-driven dynamics in steady-state stable lasers. We observe a complete suppression of the relaxation oscillation peaks in the intensity difference noise spectrum, and this is well described by linearized rate equations. The influence of both gain and index guiding is considered, together with that of relative frequency detuning