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AssigneeFurukawa Electric Co., Ltd.
InventorsNarihito Matsumoto, Akihiko Kasukawa, Takeshi Namegaya, Hiroshi Okamoto
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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 more than 160 meV so that it shows a lowered threshold current density. Besides, by selecting a thickness of the quantum-well layers between 3 and 8 nm, 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.
A quantum-well type semiconductor laser device comprising a resonant cavity, an active layer comprising no more than two quantum-well layers and a barrier layer, and a pair of Ga.sub.x In.sub.1-x As.sub.y P.sub.1-y (x.gtoreq.0, y.ltoreq.1) semiconductive optical confinement layers arranged above and below said active layer, said layers being formed on an InP substrate in a given arrangement, first and second electrodes on opposite sides, respectively of the quantum-well layer(s), and wherein the bandgap energy of the optical confinement layers is greater than that of the quantum-well layer(s) by 16 meV and the thickness of the quantum-well layer(s) is between 3 nm and 8 nm.
Dependencies are inferred from the claim text.