Abstract: The present invention provides a dual-polarized Lidar receiving end based on an optical chip, including a module for receiving reflected light, a module for receiving local oscillator light, a plurality of frequency mixers, a plurality of detectors and a plurality of variable optical attenuators. The Lidar receiving end according to the present invention can receive and process two optical signals in an orthogonal polarization state. Compared with the existing Lidar design solution, a system on chip based on the optical chip according to the present invention implements monolithic integration of massive devices, and has the advantages of high stability, small volume and low weight and costs, and the like. It is relatively easy to increase a quantity of channels at the receiving end designed according to the present invention.

Abstract: The present invention provides a silicon-based integrated optical chip integrating a silicon-based optical modulator and a germanium-silicon detector and a preparation method thereof. A position and dimension of a silicon nitride waveguide are defined by a slot formed by using an etching process, then surplus silicon nitride is removed by means of chemico-mechanical polishing, and an optical waveguide is formed by the silicon nitride in the slot.

Abstract: A self-adaptive constant-current driving circuit for a three-channel multi-color LED, including a decoder, a two-phase non-overlapping circuit, and a LED constant-current driving circuit, where the decoder determines the number of lighted channels according to a first input signal, and generates a first switch control signal and a second switch control signal; the two-phase non-overlapping circuit modulates the first switch control signal into a first two-phase non-overlapping signal and a second two-phase non-overlapping signal, and modulates the second switch control signal into a third two-phase non-overlapping signal and a fourth two-phase non-overlapping signal; the LED constant-current driving circuit controls an on/off state of the respective channel of LED according to a second input signal, and outputs a current for controlling a brightness of the respective channel of LED according to the first two-phase non-overlapping signal, the second two-phase non-overlapping signal, the third two-phase non-ove

Abstract: The present application discloses a cerebral perfusion state classification apparatus and method, a device, and a storage medium. The method includes: acquiring, by a transceiving module, cervical blood flow data from an ultrasound data collecting device; determining, by a processor, cerebral perfusion data corresponding to the cervical blood flow data based on the cervical blood flow data and a mapping relationship between the cervical blood flow data and the cerebral perfusion data, and classifying cerebral perfusion states of a plurality of brain regions based on blood perfusion characteristics of the plurality of brain regions in the cerebral perfusion data.

Abstract: A low loss snubber circuit for protecting an electronic device within a power converter is provided. The low loss snubber circuit includes a bidirectional transient voltage suppression (TVS) diode having first and second nodes, wherein the first node of the bidirectional TVS diode is coupled to a first node of the electronic device, and a snubber capacitor having first and second nodes, wherein the first node is coupled to the second node of the bidirectional TVS diode and the second node is coupled to a second node of the electronic device. The low loss snubber circuit further includes a snubber diode having an anode and a cathode, wherein the anode is coupled to the second node of the bidirectional TVS diode and the cathode is coupled to a node of the power converter.

Abstract: A power device is provided. The power device includes a current limiting resistor in series with a load, the current limiting resistor configured to provide a first current path to the load. The power device also includes an inrush current control device configured to provide a second current path to the load, the second current path configured to bypass the first current path in response to the inrush current control device being activated. The power device also includes a bypass device configured to provide a third current path to the load, the third current path configured to provide a low-resistance current path to the load during a power surge.

Abstract: The present invention provides a photodiode structure with a dark current indication function, including a photosensitive photodiode and a reference photodiode, where a photosensitive surface of the reference photodiode is provided with a light-blocking layer, and there is a fixed multiple relationship between dark currents of the photosensitive photodiode and the reference photodiode. The present invention further provides a photoelectric sensor, including a processing module and the photodiode structure. According to a structural design of the present invention, the photodiode structure may output two paths of current signals, so that an accurate signal photocurrent can be obtained only by subtracting the two paths of current signals in practice work, so as to finally achieve the objectives of eliminating the dark currents and reducing noise; and moreover, in the present invention, the dark currents of photodiodes are eliminated without increasing peripheral devices.

Abstract: The present invention provides a normal-incident photodiode structure with a dark current self-compensation function, including a photosensitive photodiode and a compensating photodiode, where a photosensitive surface of the compensating photodiode is provided with a light-blocking layer, and dark currents of the photosensitive photodiode and the compensating photodiode are equal.

Abstract: A switched-mode power supply includes an input, an output, and a transformer including primary and secondary windings. The power supply also includes a synchronous rectifier coupled to selectively conduct current through the secondary winding of the transformer. The synchronous rectifier includes a source, a gate and a drain terminal. The power supply further includes a controller having a supply voltage terminal and a gate terminal to supply a control signal to the gate of the synchronous rectifier, and a circuit coupled between the supply voltage terminal of the controller and at least one of the gate terminal of the controller and the drain terminal of the synchronous rectifier to supply power from the gate terminal of the controller or the drain terminal of the synchronous rectifier to the supply voltage terminal of the controller. Methods of supplying power in switched-mode power supplies are also disclosed.

Abstract: Various embodiments of a monolithic transceiver are described, which may be fabricated on a semiconductor substrate. The monolithic transceiver includes a coherent receiver module (CRM), a coherent transmitter module (CTM), and a local oscillation splitter to feed a local oscillation to the CRM and the CTM with a tunable power ratio. The monolithic transceiver provides tunable responsivity by employing photodiodes for opto-electrical conversion. The monolithic transceiver also employs a polarization beam rotator-splitter (PBRS) and a polarization beam rotator-combiner (PBRC) for supporting modulation schemes including polarization multiplexed quadrature amplitude modulation (PM-QAM) and polarization multiplexed quadrature phase shift keying (PM-QPSK).

Abstract: A power conversion device is provided. The power conversion device includes a bulk capacitor, a current limiting resistor in series with the bulk capacitor, and an inrush current control device configured to bypass the current limiting resistor when activated. The power conversion device also includes a bypass device in parallel with the current limiting resistor, configured to provide a low-resistance path to the bulk capacitor during a power surge.

Abstract: Various embodiments of a coplanar waveguide (CPW) transmission line as well as a silicon-based electro-optic (E-O) modulator comprising the CPW transmission line are described. The CPW transmission line has a curved or winding shape. The silicon-based E-O modulator includes a rib optical waveguide, a beam splitter, a beam combiner, and a CPW transmission line that exhibits the winding shape. At least one of the two optical arms of the rib optical waveguide alternately and periodically extends through a first groove and a second groove of the CPW transmission line. The plurality of active sections of the rib optical waveguide are evenly distributed on both sides of the CPW transmission line to suppress undesired transmission modes. An increased length of transmission path of the rib optical waveguide is also avoided or minimized, thereby reducing the transmission speed mismatch of the E-O modulator, which is essential for achieving high-speed operation.

Abstract: A power conversion device is provided. The power conversion device includes a bulk capacitor, a current limiting resistor in series with the bulk capacitor, and an inrush current control device configured to bypass the current limiting resistor when activated. The power conversion device also includes a bypass device in parallel with the current limiting resistor, configured to provide a low-resistance path to the bulk capacitor during a power surge.

Abstract: Various embodiments of a photodetector having a reflector are described. The photodetector includes a waveguide layer disposed on top of a substrate, an avalanche multiplication detection region disposed on top of the waveguide layer, and a reflector disposed adjacent to a rear surface of the waveguide layer. The waveguide layer includes a narrower input section and a wider detection section concatenated with the input section. The waveguide layer may also include a tapering section having a changing width that follows the detection section. The reflector may be a one-dimensional photonic crystal, a two-dimensional photonic crystal, or a bulk material. A careful design of the reflector and the waveguide layer of the photodetector is helpful in achieving a high responsivity and a high operation speed at the same time.

Abstract: Various embodiments of a monolithic transceiver are described, which may be fabricated on a semiconductor substrate. The monolithic transceiver includes a coherent receiver module (CRM), a coherent transmitter module (CTM), and a local oscillation splitter to feed a local oscillation to the CRM and the CTM with a tunable power ratio. The monolithic transceiver provides tunable responsivity by employing photodiodes for opto-electrical conversion. The monolithic transceiver also employs a polarization beam rotator-splitter (PBRS) and a polarization beam rotator-combiner (PBRC) for supporting modulation schemes including polarization multiplexed quadrature amplitude modulation (PM-QAM) and polarization multiplexed quadrature phase shift keying (PM-QPSK).

Abstract: Various embodiments of a coplanar waveguide (CPW) transmission line as well as a silicon-based electro-optic (E-O) modulator comprising the CPW transmission line are described. The CPW transmission line has a curved or winding shape. The silicon-based E-O modulator includes a rib optical waveguide, a beam splitter, a beam combiner, and a CPW transmission line that exhibits the winding shape. At least one of the two optical arms of the rib optical waveguide alternately and periodically extends through a first groove and a second groove of the CPW transmission line. The plurality of active sections of the rib optical waveguide are evenly distributed on both sides of the CPW transmission line to suppress undesired transmission modes. An increased length of transmission path of the rib optical waveguide is also avoided or minimized, thereby reducing the transmission speed mismatch of the E-O modulator, which is essential for achieving high-speed operation.

Abstract: Various embodiments of a monolithic transceiver are described, which may be fabricated on a semiconductor substrate. The monolithic transceiver includes a coherent receiver module (CRM), a coherent transmitter module (CTM), and a local oscillation splitter to feed a local oscillation to the CRM and the CTM with a tunable power ratio. The monolithic transceiver provides tunable responsivity by employing avalanche photodiodes (APDs) for opto-electrical conversion. The monolithic transceiver also employs a polarization beam rotator-splitter (PBRS) and a polarization beam rotator-combiner (PBRC) for supporting modulation schemes including polarization multiplexed quadrature amplitude modulation (PM-QAM) and polarization multiplexed quadrature phase shift keying (PM-QPSK).

Abstract: A switched-mode power supply includes an input, an output, and a transformer including primary and secondary windings. The power supply also includes a synchronous rectifier coupled to selectively conduct current through the secondary winding of the transformer. The synchronous rectifier includes a source, a gate and a drain terminal. The power supply further includes a controller having a supply voltage terminal and a gate terminal to supply a control signal to the gate of the synchronous rectifier, and a circuit coupled between the supply voltage terminal of the controller and at least one of the gate terminal of the controller and the drain terminal of the synchronous rectifier to supply power from the gate terminal of the controller or the drain terminal of the synchronous rectifier to the supply voltage terminal of the controller. Methods of supplying power in switched-mode power supplies are also disclosed.

Abstract: Various embodiments of a monolithic electro-optical (E-O) modulator are described. The monolithic E-O modulator includes an active region comprising a plurality of p-n junction diodes, as well as a modulation electrode and a bias electrode that extend through the active region. The monolithic E-O modulator further includes a resistor-capacitor-bias-capacitor (RCBC) electrode structure configured to receive an electrical modulation signal, a direct-current (DC) bias voltage and a power supply voltage. Specifically, the RCBC electrode structure includes a resistor coupled to the modulation electrode and two capacitors each coupled to a respective end of the bias electrode. Beneficially, the RCBC electrode structure enables the p-n junction diodes to be biased independently from a DC level of the electrical modulation signal.

Abstract: A switched-mode power supply includes an input, an output, and a transformer including primary and secondary windings. The power supply also includes a synchronous rectifier coupled to selectively conduct current through the secondary winding of the transformer. The synchronous rectifier includes a source, a gate and a drain terminal. The power supply further includes a controller having a supply voltage terminal and a gate terminal to supply a control signal to the gate of the synchronous rectifier, and a circuit coupled between the supply voltage terminal of the controller and at least one of the gate terminal of the controller and the drain terminal of the synchronous rectifier to supply power from the gate terminal of the controller or the drain terminal of the synchronous rectifier to the supply voltage terminal of the controller. Methods of supplying power in switched-mode power supplies are also disclosed.