A laser device is disclosed which stabilizes impedance at laser drive
initiation, and in which an oscillation at low current, a high reaction
speed, a low noise, and the like are achieved. A semiconductor laser
device includes first and second conductive type semiconductor layers, an
active layer, and first and second electrodes. The second electrode
comprises an ohmic electrode and a pad electrode. The first electrode is
formed on the same planar side of the first conductive type semiconductor
layer as the second electrode, and is disposed in the same direction as
the pad electrode with respect to the ohmically connected region. The
second conductive type semiconductor layer is set to a width that can
secure light confinement on both sides of the ohmically connected region.