Spontaneous spatiotemporal instabilities in current modulated master oscillator power amplifier lasers

We provide the first comprehensive theoretical evidence for nonlinear space-time dynamical behavior which seriously degrades the performance of a monolithically integrated master oscillator power amplifier laser under direct current modulation of the master oscillator. A host of instabilities, reflecting dynamical behavior of different sections of the device, are possible. These instabilities are due to the combination of weak feedback from the power amplifier section of the device causing leakage into the master oscillator section, from the buildup of unsaturated carriers along the narrow edges of the expanding flare and differential saturation of the passive regions under the distributed Bragg reflector grating sections.