Abstract

In this paper we present the first observation of passive mode-locking in a quantum dot (QD) ring laser operating at wavelengths around 1.5 μm. The InAs/InP QD laser structure is grown on n-type (100) InP substrates by metal-organic vapor-phase epitaxy [1]. Lasers with a ring configuration are realized using the fabrication technology presented in [2]. The device consists of an 18-mm long (electrically pumped) ring cavity, corresponding to a 5-GHz roundtrip frequency. The ridge waveguide width is 2 μm. A saturable absorber (SA) section with a length of 300 μm is located in the cavity. The position of the SA in the ring is opposite to a directional coupler which couples 5% - 10% of the light to the output waveguides. The output waveguides end with angled facets that have been anti-reflection coated to suppress feedback into the cavity.

© 2009 IEEE