Broadband Emission in Quantum-Dash Semiconductor Laser

A new type of semiconductor laser is studied, in which injected carriers in the active region are quantum mechanically confined in localized finite self-assembled wire-like quantumdash (Qdash) structures that are varied in sizes and compositions. Effects of such carrier distribution and quasi three-dimensional density of states contribute to a quasisupercontinuum interband lasing characteristics, which is a new laser design platform as compared to continuous broad emission spectrum generated by nonlinear media pumped with ultrashort laser pulse. The wavelength profile of quasi-supercontinuum emission is tunable at near-infrared wavelength spanning across several optical communication bands at around ~1500 nm in addition to the ability of operating condition at room temperature as opposed to that previously obtained only at operating temperature below 100 K. In this chapter, a thorough analysis of the Qdash material system, device physics and the establishment of ultrabroad stimulated emission behavior will be presented and discussed.