An edge emitting semiconductor laser suppresses the "beam steering" to raise
its
maximum output with a simple configuration. An optical waveguide serving as a resonator
includes an active layer and a cladding layer. A first edge, to which one end of
the waveguide is connected, serves as an emission edge. A second edge, to which
the other end of the waveguide is connected, is located at an opposite side to
the first edge. The waveguide includes at least two parts having different widths,
one of the at least two parts being a fundamental mode section. Current injection
suppressing means is provided for suppressing or controlling current injection
into the active layer in at least part of the fundamental mode section. The current
injection suppressing means is preferably made by a current blocking layer, a current-limiting
masking layer, or a passive wave-guiding region.
