A semiconductor light-emitting device includes a first submount and a semiconductor light-emitting chip. The semiconductor light-emitting chip includes a first surface, a first optical waveguide extending in a first direction parallel to the first surface and disposed closer to the first surface than to a second surface, and an emission surface that emits emission light. The first submount includes a first base including a third surface, and a spacer disposed on the third surface. The semiconductor light-emitting chip is bonded to the first submount with the first surface facing the spacer. The emission surface is positioned forward of a front end surface of the spacer. A first front surface, which is the front end surface of the first base, is positioned forward of the emission surface.

A semiconductor optical device includes: a base configured to intersect with a first direction; a first protrusion configured to protrude from the base in the first direction, the first protrusion including a planar lightwave circuit including: a core layer; and a cladding layer surrounding the core layer; a second protrusion configured to protrude from the base in the first direction and arranged along the first protrusion in a second direction intersecting with the first direction, a height of the second protrusion from the base in the first direction being lower than a height of the first protrusion; an optical semiconductor element placed on a facet of the second protrusion in the first direction and optically connected to the core layer; and a marker provided on the second protrusion in a manner exposed on the facet, the marker being made of a same material as the core layer.

A semiconductor optical device includes: a base configured to intersect with a first direction; a first protrusion configured to protrude from the base in the first direction, the first protrusion including a planar lightwave circuit including: a core layer; and a cladding layer surrounding the core layer; a second protrusion configured to protrude from the base in the first direction and arranged along the first protrusion in a second direction intersecting with the first direction, a height of the second protrusion from the base in the first direction being lower than a height of the first protrusion; an optical semiconductor element placed on a facet of the second protrusion in the first direction and optically connected to the core layer; and a marker provided on the second protrusion in a manner exposed on the facet, the marker being made of a same material as the core layer.

A first conductive pattern (13) is provided on an upper surface of the submount (7). A GND pattern (9) is provided on a lower surface of the submount (7). A lower surface electrode (21) of a capacitor (3) is bonded to the first conductive pattern (13) with solder (22). An upper surface electrode (23) of the capacitor (3) is connected to a light emitting device (2). A terminating resistor (4) is connected to the first conductive pattern (13). The first conductive pattern (13) has a protruding portion (25) which protrudes outside from the capacitor (3) in planar view. A width of the protruding portion (25) is narrower than a width of the capacitor (3).

A first conductive pattern (13) is provided on an upper surface of the submount (7). A GND pattern (9) is provided on a lower surface of the submount (7). A lower surface electrode (21) of a capacitor (3) is bonded to the first conductive pattern (13) with solder (22). An upper surface electrode (23) of the capacitor (3) is connected to a light emitting device (2). A terminating resistor (4) is connected to the first conductive pattern (13). The first conductive pattern (13) has a protruding portion (25) which protrudes outside from the capacitor (3) in planar view. A width of the protruding portion (25) is narrower than a width of the capacitor (3).

An optoelectronic semiconductor chip comprises a semiconductor body including a plurality of active regions configured to generate electromagnetic radiation, the plurality of active regions being arranged in a horizontal plane. The optoelectronic semiconductor chip further comprises a conductive member configured to electrically connect at least two adjacent ones of the active regions with each other, the conductive member being arranged over a first main surface of the semiconductor body. The optoelectronic semiconductor chip further comprises a contact element extending from the first main surface to a second main surface of the semiconductor body and being electrically connected to at least one of the active regions via a contact material over the first main surface, and an optical element arranged over the first main surface of the semiconductor body.

The laser module includes a QCL element, a diffraction grating unit, a first lens holder, a second lens holder, and a mount member. The first mounting portion has a first top surface on which the first lens holder is mounted via an adhesive layer. The third mounting portion has a third top surface on which the second lens holder is mounted via an adhesive layer. The second mounting portion has a second top surface located higher than the first top surface and the third top surface, a first side surface connecting the second top surface and the first top surface, and a second side surface connecting the second top surface and the third top surface. A notch extending from the second top surface to the first top surface or the third top surface is formed in at least one of the first side surface and the second side surface.

The laser module includes a QCL element, a diffraction grating unit, a first lens holder, a second lens holder, and a mount member. The first mounting portion has a first top surface on which the first lens holder is mounted via an adhesive layer. The third mounting portion has a third top surface on which the second lens holder is mounted via an adhesive layer. The second mounting portion has a second top surface located higher than the first top surface and the third top surface, a first side surface connecting the second top surface and the first top surface, and a second side surface connecting the second top surface and the third top surface. A notch extending from the second top surface to the first top surface or the third top surface is formed in at least one of the first side surface and the second side surface.

A light emitting device includes semiconductor laser elements, a frame part, a light-reflective member, a step part, metal films, wires, and a first protective element. The frame part surrounds a bottom surface on which the semiconductor laser elements are disposed. The light-reflective member is disposed on the bottom surface inside of a frame formed by the frame part. The step part is formed along a second inner lateral surface of the frame part, and disposed inside of the frame. The metal films are provided on an upper surface of the step part. The wires electrically connect the semiconductor laser elements respectively to the metal films. The first protective element is disposed on the upper surface of the step part and on a light traveling side of the laser light with respect to a plane including an emitting end surface of the first semiconductor laser element.

A light emitting device includes semiconductor laser elements, a frame part, a light-reflective member, a step part, metal films, wires, and a first protective element. The frame part surrounds a bottom surface on which the semiconductor laser elements are disposed. The light-reflective member is disposed on the bottom surface inside of a frame formed by the frame part. The step part is formed along a second inner lateral surface of the frame part, and disposed inside of the frame. The metal films are provided on an upper surface of the step part. The wires electrically connect the semiconductor laser elements respectively to the metal films. The first protective element is disposed on the upper surface of the step part and on a light traveling side of the laser light with respect to a plane including an emitting end surface of the first semiconductor laser element.