Broadband light source using modulated quantum dot structures with sandwiched sub-nano separator (SSNS) technique

A broadband light source for a wavelength range of around 1.2‐1.3 μm can be fabricated using a multi‐stacked and modulated InAs/InGaAs quantum dot (QD) structure with the sandwich sub‐nano separator (SSNS) technique. These techniques, such as use of the modulated QD structure and SSNS structure, are considered useful in obtaining a high‐quality and ultra‐broadband QD optical gain material for the laser and/or optical amplifier. A broadband (>75 nm bandwidth) and bright (few tenths of a mW) light emission in its waveband is successfully demonstrated from a QD laser diode using a modulated QD optical gain with the SSNS technique. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)