Abstract

The growth of defect free semiconductor quantum dots via the Stranski-Krastanov (S-K) growth mode has lead to a wide range of novel laser characteristics and performance improvements over quantum well devices. The 0-D nature of the confined states in quantum dots has resulted in devices with ultra-low, temperature independent threshold currents; and a close to zero linewidth enhancement factor. The S-K growth mode produces a range of dot sizes leading to an inhomogeneous broadening of the gain spectrum in laser devices. This means we can engineer the width of the gain spectrum to achieve particular characteristics. A small inhomogeneous broadening is required if we want devices with characteristics such as a low threshold current. Devices with a high degree of inhomogeneous broadening offer the possibility of ultra-short pulse generation via mode locking techniques. For example a 100meV wide gain spectrum should result in optical pulses with a width of 3fs. The width of the pulses and the repetition rates will however be governed by the unique carrier-photon interaction dynamics in quantum dot systems.

© 2002 Optical Society of America