Abstract: An embodiment of the present invention provides a photodetector chip, including a substrate, a semiconductor optical amplification section, and a photodetection section. The substrate includes a surface, the photodetection section and the semiconductor optical amplification section are arranged on the substrate, and the photodetection section is located in an optical signal output direction of the semiconductor optical amplification section. The semiconductor optical amplification section amplifies and filters an input optical signal to output an amplified and filtered optical signal to the photodetection section. The photodetection section is configured to convert the amplified and filtered optical signal into an electrical signal. The semiconductor optical amplification section includes a grating, the grating includes a first grating and a second grating that are cascaded, and the first grating is a slanted grating.

Abstract: An optical modulation and amplification apparatus, an optical module, an optical network unit, and an optical communication system are provided. The optical modulation and amplification apparatus includes an electric absorption modulator and a semiconductor optical amplifier. The electric absorption modulator and the semiconductor optical amplifier share a same substrate and a same multi-layer material structure. The multi-layer material structure includes, from bottom to top, at least a first quantum well, an electron blocking layer, a second quantum well, and an upper separate confinement layer. The electric absorption modulator is configured to modulate injection light by using the first quantum well, and the semiconductor optical amplifier is configured to amplify the injection light by using the second quantum well.

Abstract: A laser chip includes a first power detector, a first controller, an optical splitter, a polarization splitter-rotator, a bandpass filter, and a slave laser. The optical splitter includes a first, a second, and a third port. The first port is configured to receive injection light of a master laser. The second port is connected to the first power detector. The optical splitter is configured such that the injection light enters the optical splitter through the first port, and is output to the polarization splitter-rotator through the third port. The polarization splitter-rotator is configured to perform optical splitting and polarization conversion on the injection light. The polarization splitter-rotator includes a first waveguide configured to transmit TE mode injection light after the injection light is split by the polarization splitter-rotator, and a second waveguide configured to transmit TM mode injection light after the injection light is split by the polarization splitter-rotator.

Abstract: Example optical devices are described. One example optical device includes a receiver. The receiver includes a photodetector, a first amplifier, a second amplifier, and a controller, where the photodetector is coupled to the first amplifier, the first amplifier is coupled to the second amplifier, and the first amplifier and the second amplifier are separately coupled to the controller. The controller is configured to control a gain of the first amplifier and a gain of the second amplifier based on a preset arrival time of an optical signal and a gain intensity corresponding to the optical signal. The photodetector is configured to receive the optical signal and convert the optical signal into a current signal. The first amplifier is configured to convert the current signal into a first voltage signal. The second amplifier is configured to convert the first voltage signal into a second voltage signal.

Abstract: An optical transmitter includes a light source and an adjustment structure. The light source is configured to output an original light spot, to transmit a test optical signal to a skin of a user. The adjustment structure is located on an output optical path of the test optical signal.

Abstract: Example optical devices are described. One example optical device includes a receiver. The receiver includes a photodetector, a first amplifier, a second amplifier, and a controller, where the photodetector is coupled to the first amplifier, the first amplifier is coupled to the second amplifier, and the first amplifier and the second amplifier are separately coupled to the controller. The controller is configured to control a gain of the first amplifier and a gain of the second amplifier based on a preset arrival time of an optical signal and a gain intensity corresponding to the optical signal. The photodetector is configured to receive the optical signal and convert the optical signal into a current signal. The first amplifier is configured to convert the current signal into a first voltage signal. The second amplifier is configured to convert the first voltage signal into a second voltage signal.

Abstract: A semiconductor laser, an optical transmitter component, an optical line terminal, and an optical network unit. The semiconductor laser includes a substrate, a lower waveguide layer, a lower confining layer, a central layer, an upper confining layer, a grating layer, an upper waveguide layer, and an electrode layer that are sequentially formed on the substrate. The upper confining layer, the central layer, and the lower confining layer in a filtering region form a core layer of the filtering region. The grating layer in the filtering region includes a slanted grating. Thus, a modulation chirp and dispersion of a transmitted optical pulse can be reduced.

Abstract: An embodiment of the present invention provides a photodetector chip, including a substrate, a semiconductor optical amplification section, and a photodetection section. The substrate includes a surface, the photodetection section and the semiconductor optical amplification section are arranged on the substrate, and the photodetection section is located in an optical signal output direction of the semiconductor optical amplification section. The semiconductor optical amplification section amplifies and filters an input optical signal to output an amplified and filtered optical signal to the photodetection section. The photodetection section is configured to convert the amplified and filtered optical signal into an electrical signal. The semiconductor optical amplification section includes a grating, the grating includes a first grating and a second grating that are cascaded, and the first grating is a slanted grating.