| abstract |
A semiconductor laser device comprises a semiconductor assembly which serves to effect laser oscillation and in which first, second and third semiconductor layers (2,3,4) are successively stacked on a predetermined semiconductor body (1), at least the first and third semiconductor layers (2,4) having a smaller refractive index and a greater forbidden band gap relative than the second semiconductor layer (3) and having conductivity types opposite to each other, and means (6, 8) to spread depletion regions within at least a part of a current path for effecting the laser oscillation and in a manner to intersect with the current path. A small-sized semiconductor laser device capable of fast modulation can be realized. |