QUANTUM WELL SEMICONDUCTOR LASER DEVICE

摘要

In a quantum-well type semiconductor laser device comprising a multi-layered quantum-well layer (active layer) constituted by quantum-well layers and a corresponding number of barrier layers and a pair of optical confinement layers respectively arranged on and under the active layer, since the number of quantum-well layers is limited to one or two, the device has a reduced internal loss, a narrowed far-field angle and a bandgap energy of the quantum-well layers greater than that of the optical confinement layers by 160meV ox more so that it shows a lowered threshold current density. Besides, by selecting a thickness of the quantum-well layers between 3 and 8nm, the device can be made to oscillate at the first quantum level in order to make the oscillation wavelength highly dependent on temperature and optical output and accordingly produce a high spectral purity.