Abstract

Passively mode-locked two-section quantum-dot monolithic semiconductor lasers are promising optical pulse sources for medical imaging and communication applications. Their advantages are their compactness, ease of operation and high efficiency compared to solid state lasers. Quantum-dots (QD) incorporated as the active medium in a diode laser offer peculiar advantages like low threshold current and broad gain bandwidth. Implemented as a tapered structure high pulse peak power can be accessed [2]. However, pulse train amplitude is still affected by temporal instabilities. One of them is the self-pulsation instability, where the pulse amplitudes are modulated by passive Q-switching at lower frequencies up to the GHz range. The shortest pulses which are suitable for many applications occur at low gain currents. In this region operation is often afflicted by these instabilities. By proper laser structure design in terms of internal device parameters these instabilities may be avoided [1]. However, this approach cannot be performed after device production.

© 2011 Optical Society of America