Semiconductor laser, optical transmitter component, optical line terminal, and optical network unit

An optical line terminal (OLT), comprising:

• an optical transmitter component, wherein the optical transmitter component comprises a semiconductor laser comprising:
• a substrate and a layer body comprising:
• a lower waveguide layer,
• a lower confining layer,
• a central layer made of indium gallium aluminum arsenide, wherein a thickness of the central layer in a preset direction is in a range between 100 nm and 200 nm, and the preset direction is a direction from an end close to the substrate to an end away from the substrate
• an upper confining layer, wherein the upper confining layer and the lower confining layer are configured to limit carriers and photons,
• a grating layer,
• an upper waveguide layer, and
• a first electrode layer that are sequentially formed on the substrate in the preset direction, wherein the layer body is divided into;
• a laser region,
• a first isolation region, and
• a filtering region in a cavity length direction, the first isolation region is located between the laser region and the filtering region, the first isolation region comprises a groove formed by etching the first electrode layer, the first electrode layer in the laser region is configured to receive a first electrical excitation signal, the upper confining layer, the central layer, and the lower confining layer in the laser region form an active layer of the laser region, to generate and transmit an optical signal under an action of the first electrical excitation signal, the upper confining layer, the central layer, and the lower confining layer in the filtering region form a core layer of the filtering region, to transmit a filtered optical signal, the grating layer in the laser region comprises:
• a Bragg grating configured to select a single longitudinal mode, wherein the Bragg grating is a complex coupled grating comprising both a refractive index-coupled grating and a gain-coupled grating, and the grating layer in the filtering region comprises a slanted grating configured to perform optical filtering.

An optical network unit (ONU), comprising an optical transmitter component, wherein the optical transmitter component comprises a semiconductor laser comprising a substrate and a layer body comprising:

• a lower waveguide layer,
• a lower confining layer,
• a central layer made of indium gallium aluminum arsenide, wherein a thickness of the central layer in a preset direction is in a range between 100 nm and 200 nm, and the preset direction is a direction from an end close to the substrate to an end away from the substrate,
• an upper confining layer, wherein the upper confining layer and the lower confining layer are configured to limit carriers and photons,
• a grating layer,
• an upper waveguide layer, and
• a first electrode layer that are sequentially formed on the substrate in the preset direction, wherein the layer body is divided into:
• a laser region,
• a first isolation region, and
• a filtering region in a cavity length direction, the first isolation region is located between the laser region and the filtering region, the first isolation region comprises a groove formed by etching the first electrode layer, the first electrode layer in the laser region is configured to receive a first electrical excitation signal, the upper confining layer, the central layer, and the lower confining layer in the laser region form an active layer of the laser region, to generate and transmit an optical signal under an action of the first electrical excitation signal, the upper confining layer, the central layer, and the lower confining layer in the filtering region form a core layer of the filtering region, to transmit a filtered optical signal, the grating layer in the laser region comprises:
• a Bragg grating configured to select a single longitudinal mode, wherein the Bragg grating is a complex coupled grating comprising both a refractive index-coupled grating and a gain-coupled grating, and the grating layer in the filtering region comprises a slanted grating configured to perform optical filtering.