Abstract: This application provides a port detection method and apparatus. In the technical solutions in this application, an OLT or an ONU may determine, based on at least two wavelengths and a preset correspondence, port information that is of an optical splitter and that corresponds to the ONU. That is, a branch port directly or indirectly connected to the ONU is defined by using the at least two wavelengths. In this way, different branch ports can be distinguished by using combinations of a plurality of wavelengths, to define a large quantity of branch ports of the optical splitter by using free combinations of a small quantity of wavelengths.

Abstract: This application provides a port detection method, an optical network device, and a passive optical network system, to quickly and accurately detect a port connected to an ONU, and improve efficiency of determining the port connected to the ONU. The method includes: an optical line terminal sends optical signals corresponding to all of N wavelengths to at least one optical network unit, where the N wavelengths are different from each other, and N is a positive integer; the OLT receives optical power values that are of the optical signals corresponding to all of the N wavelengths and that are sent by a first ONU, where the first ONU is any one of the at least one ONU; and the OLT determines, bases on the optical power values of the optical signals corresponding to all of the N wavelengths, information about an optical splitter port corresponding to the first ONU.

Abstract: A transmitter optical subassembly is disclosed including a substrate and a direct modulated laser disposed on the substrate. A single-stage isolator, a polarization direction rotator, and an optical branching filter are disposed side by side on the substrate in a light propagation direction. The polarization direction rotator can adjust linearly polarized light to P-polarized light, the optical branching filter includes an optical splitter subassembly and a filter subassembly, and an optical splitter film in the optical splitter subassembly is an optical splitter film with P polarization. The polarization direction rotator adjusts the incident linearly polarized light to the P-polarized light, and the optical splitter film in the optical branching filter is the optical splitter film with P polarization; all P-polarized light with single polarization can pass through the optical branching filter, without causing any polarization loss or two peaks.

Abstract: A collimation lens and an optical module of the collimation lens. The collimation lens includes a front convex aspheric lens, a first polarizing filter, a Faraday rotation (FR) crystal, a second polarizing filter, and a rear convex aspheric lens. The front convex aspheric lens is coupled to a first end face of the collimation lens, and the rear convex aspheric lens is coupled to a second end face of the collimation lens. The first polarizing filter is coupled between the front convex aspheric lens and the FR crystal, and the second polarizing filter is coupled between the FR crystal and the rear convex aspheric lens.

Abstract: A transmitter optical subassembly is disclosed including a substrate and a direct modulated laser disposed on the substrate. A single-stage isolator, a polarization direction rotator, and an optical branching filter are disposed side by side on the substrate in a light propagation direction. The polarization direction rotator can adjust linearly polarized light to P-polarized light, the optical branching filter includes an optical splitter subassembly and a filter subassembly, and an optical splitter film in the optical splitter subassembly is an optical splitter film with P polarization. The polarization direction rotator adjusts the incident linearly polarized light to the P-polarized light, and the optical splitter film in the optical branching filter is the optical splitter film with P polarization; all P-polarized light with single polarization can pass through the optical branching filter, without causing any polarization loss or two peaks.

Abstract: An arrayed waveguide grating includes an input/output waveguide 1, an input/output waveguide 2, a slab waveguide, an arrayed waveguide 1, a reflection zone 1, an arrayed waveguide 2, and a reflection zone 2. The input/output waveguide 1 and the input/output waveguide 2 are located on a same side of the slab waveguide, and are coupled to the slab waveguide. The reflection zone 1 is configured to reflect a light wave in a first band, and to transmit a light wave in a second band. The reflection zone 2 is configured to reflect the light wave in the second band. It is implemented that a single arrayed waveguide grating outputs light waves with different adjacent channel wavelength spacings, and a quantity of devices used in a system in which an uplink adjacent channel wavelength spacing and a downlink adjacent channel wavelength spacing are asymmetrical is further reduced.

Abstract: An arrayed waveguide grating includes an input/output waveguide 1, an input/output waveguide 2, a slab waveguide, an arrayed waveguide 1, a reflection zone 1, an arrayed waveguide 2, and a reflection zone 2. The input/output waveguide 1 and the input/output waveguide 2 are located on a same side of the slab waveguide, and are coupled to the slab waveguide. The reflection zone 1 is configured to reflect a light wave in a first band, and to transmit a light wave in a second band. The reflection zone 2 is configured to reflect the light wave in the second band. It is implemented that a single arrayed waveguide grating outputs light waves with different adjacent channel wavelength spacings, and a quantity of devices used in a system in which an uplink adjacent channel wavelength spacing and a downlink adjacent channel wavelength spacing are asymmetrical is further reduced.

Abstract: A collimation lens and an optical module of the collimation lens. The collimation lens includes a front convex aspheric lens, a first polarizing filter, a Faraday rotation (FR) crystal, a second polarizing filter, and a rear convex aspheric lens. The front convex aspheric lens is coupled to a first end face of the collimation lens, and the rear convex aspheric lens is coupled to a second end face of the collimation lens. The first polarizing filter is coupled between the front convex aspheric lens and the FR crystal, and the second polarizing filter is coupled between the FR crystal and the rear convex aspheric lens.

Abstract: A method includes monitoring a power value of output light of the laser and a power value of reflected light, obtaining an insertion loss value according to the power value of the output light, the power value of the reflected light, and a parameter of a Faraday rotation reflector, obtaining a bias current value according to the insertion loss value, and adjusting the power value of the output light of the laser using the bias current value. The insertion loss value is obtained by detecting the power value of the reflected light obtained after the output light of the laser is reflected. Because the insertion loss value is a power loss value, of the output light of the laser, on a one-way link between the laser and the Faraday rotation mirror.

Abstract: A method includes monitoring a power value of output light of the laser and a power value of reflected light, obtaining an insertion loss value according to the power value of the output light, the power value of the reflected light, and a parameter of a Faraday rotation reflector, obtaining a bias current value according to the insertion loss value, and adjusting the power value of the output light of the laser using the bias current value. The insertion loss value is obtained by detecting the power value of the reflected light obtained after the output light of the laser is reflected. Because the insertion loss value is a power loss value, of the output light of the laser, on a one-way link between the laser and the Faraday rotation mirror.