Broadband superluminescent diodes with height-engineered InAs-GaAs quantum dots

Abstract

Ultra-wide bandwidth superluminescent diodes (SLDs) using multiple layers of InAs-GaAs quantum dots (QDs) with engineered height are realised. A tilted and tapered active region is used to reduce the effective reflectivity from the facets. A 3 dB emission bandwidth up to 140 nm centred at 1100 nm is achieved at a continuous-wave drive-current of 600 mA. It is shown that varying the height of the dots from one layer of dots to another within the active region considerably broadens the emission spectrum of the QD-SLDs compared to those made of similar layers of inhomogeneous QDs.