Semiconductor laser device

In a semiconductor laser device for radiating a laser beam from a double heterostructure section in which injected carriers having an energy source of the laser beam are confined, comprising:

• a compound semiconductor substrate with a prescribed lattice constant for loading the double heterostructure section;
• a latticed mismatched active layer with a first lattice constant which is 0.3% to 2.5% larger than the prescribed lattice constant of the substrate in the double heterostructure section for radiating the laser beam, an energy band-gap of the lattice mismatched active layer being smaller than that of a crystal with the prescribed lattice constant from which the laser beam is radiated;
• a first cladding layer with no natural superlattice structure for confining the injected carriers in the active layer,
• (1) the first cladding layer being grown on one side of the lattice mismatched active layer in the double heterostructure section,
• (2) the first cladding layer making an epitaxial junction with the active layer, and
• (3) an energy band-gap of the first cladding layer being larger than that of a crystal with a natural superlattice regularly directed in a <111>
• direction which confines the injected carriers in the active layer;
• and
• a second cladding layer grown on another side of the active layer in the double heterostructure section for confining the injected carriers in the active layer by cooperating with the first cladding layer.

In a semiconductor laser device for radiating a laser beam by confining injected carriers having an energy source of the laser beam, comprising:

• a compound semiconductor substrate which is formed by a crystal with a prescribed lattice constant and has a specific plane direction which leans by a prescribed angel toward a predetermined direction equivalent to a <011>
• direction from a (100) plane;
• a first cladding layer grown on the substrate at an epitaxial junction;
• a lattice mismatched active layer with a first lattice constant which is 0.5% to 2.0% larger than the prescribed lattice constant of the substrate for radiating the laser beam,
• (1) the active layer being grown on the first cladding layer at an epitaxial junction, and
• (2) an energy band-gap of the lattice mismatched active layer being smaller than that of a crystal with the prescribed lattice constant from which the laser beam is radiated;
• and
• a second cladding layer grown on the active layer at an epitaxial junction for confining the injected carriers in the active layer by co-operating with the first cladding layer.