Abstract: In a semiconductor laser device that includes: a semiconductor laser element that outputs light from an output portion; and a metal stem that holds the semiconductor laser element, the metal stem includes a base that has a reference surface on an upper surface and a protrusion portion that protrudes upward from the reference surface, and the protrusion portion is provided with an installation surface on which the semiconductor laser element is installed and a side surface which is disposed on an identical plane with a part of an outer circumferential surface of the base.

Abstract: In a semiconductor laser device that includes: a semiconductor laser element that outputs light from an output portion; and a metal stem that holds the semiconductor laser element, the metal stem includes a base that has a reference surface on an upper surface and a protrusion portion that protrudes upward from the reference surface, and the protrusion portion is provided with an installation surface on which the semiconductor laser element is installed and a side surface which is disposed on an identical plane with a part of an outer circumferential surface of the base.

Abstract: A resonator in a semiconductor laser device includes a semiconductor substrate, an n-type cladding layer and a p-type cladding layer formed on or above the semiconductor substrate, and an active layer sandwiched between the n-type cladding layer and the p-type cladding layer. A ridge extending in an axial direction of the resonator is formed at an upper surface of the resonator. The ridge includes an emitting-side end portion, a non-emitting-side end portion, a taper portion allowing a width of the ridge to be decreased in a taper-like manner from the emitting-side end portion toward the non-emitting-side end portion, and a step portion provided on a side of the emitting-side end portion with respect to the non-emitting-side end portion, and allowing the width of the ridge to be changed in a step-like manner.

Abstract: A method for manufacturing a semiconductor laser device is provided in which deformation of a cap layer and a third cladding layer is inhibited and a protruding portion of an intermediate layer is removed. By coating outer peripheral portions facing an intermediate layer of a third cladding layer and an etching stop layer with a resist, inevitably removing at least the third cladding layer, and etching the intermediate layer and a cap layer in a second etching step, a protruding portion of the intermediate layer is removed, and the cap layer is prevented from being etched undesirably, whereby a ridge portion without irregularities with respect to a direction substantially perpendicular to a lamination direction is produced, and increase of an operation voltage and decrease of external differential quantum efficiency are prevented.

Abstract: A method for manufacturing a semiconductor laser device is provided in which deformation of a cap layer and a third cladding layer is inhibited and a protruding portion of an intermediate layer is removed. By coating outer peripheral portions facing an intermediate layer of a third cladding layer and an etching stop layer with a resist, inevitably removing at least the third cladding layer, and etching the intermediate layer and a cap layer in a second etching step, a protruding portion of the intermediate layer is removed, and the cap layer is prevented from being etched undesirably, whereby a ridge portion without irregularities with respect to a direction substantially perpendicular to a lamination direction is produced, and increase of an operation voltage and decrease of external differential quantum efficiency are prevented.

Abstract: A self-pulsation type semiconductor laser device includes a semiconductor substrate of a first conductive type and a multilayered structure including at least an active layer provided on the semi conductor substrate. The multilayered structure includes a first cladding layer of the first conductive type provided below the active layer, a second cladding layer of a second conductive type having a striped ridge portion provided above the active layer and a saturable absorbing film provided over the second cladding layer. The saturable absorbing film includes an accumulation region for accumulating photoexcited carriers. The accumulating region is provided apart from a surface of the second cladding layer.