A data transmission system used between counter rotating bodies and the design method of the system consisting of a data acquisition unit, one-to-N1 branching unit, N1 launching units, N2 all-in-one combiner, N2 receiving units and data processing equipment. N1 launching units and one-to-N1 branching unit are set on one counter rotating body; N2 all-in-one combiner and N2 receiving units are set on the other counter rotating body; one of the launching units and one of the receiving units are arranged on the closed movement path of the rotating body, and the maximum interval between two adjacent units of the other one is the closed movement path divided by its number and then deducted by the working range of the former one. One pair or several pairs of N1 launching units and N2 receiving units, of which the working range coincides with each other, have data transmission.

A pair of optical components is used in an isolator that enables electric isolation. Each of the optical components includes: first lens portions arranged on different optical paths and transmitting light in a first direction; second lens portions arranged on different optical paths and transmitting light in the second direction orthogonal to the first direction; and a reflection portion reflecting, in the second direction, the light in the first direction transmitted through the first lens portion and guiding the light to the second lens portion, or reflecting, in the first direction, the light in the second direction transmitted through the second lens portion and guiding the light to the first lens portion The second lens portion included in one of the pair of optical components and the second lens portion included in the other optical component are spaced apart from each other and face each other.

An on-board communication system includes an optical coupler that includes multiple optical transmission lines, and multiple on-board devices that are capable of communicating with each other with the optical coupler interposed therebetween.

A control device of modulating signal generates high-side signal and low-side signal. The high-side signal takes level in accordance with level of AC component of a monitor signal obtained by photoelectric conversion of modulated light, when the polarity of the AC component is positive, or its magnitude is zero. The high-side signal further takes constant level when the polarity of the AC component is negative. The low-side signal takes constant level when the polarity of the AC component is positive. The low-side signal further takes level in accordance with level of the AC component when the polarity of the AC component is negative, or its magnitude is zero. Then, the control device adjusts level of the modulating signal based on a greatest value of absolute values of levels taken by the high-side signal and a greatest value of absolute values of levels taken by the low-side signal.

An optical transmitter includes photonic integrated circuits configured to respectively output optical transmission signals in different wavelength ranges. A photonic integrated circuit may include emitters configured to emit beams having different wavelengths; drivers configured to respectively provide power to the emitters, and a wavelength division multiplexer configured to transmit the beams emitted by the emitters. A photonic integrated circuit may include a switch device that controls the drivers, and light detectors configured to detect intensities of the beams emitted from the emitters. The switch device may selectively operate at least one driver of the plurality of drivers based on information associated with intensities of the beams. The switch device may selectively operate a driver connected to an emitter, based on a determination that an intensity of a beam emitted by another emitter is less than a threshold intensity value.

An underwater bi-directional wireless image data communication system includes a wireless image communication device having a comparison processing device for converting an image signal about image data from an image device into an electrical signal, a light emitting unit for receiving the electrical signal from the comparison processing device and converting the electrical signal into an optical signal to output light, and a light receiving unit for receiving an external optical signal and converting the external optical signal into an electrical signal to be output as an image, and an illumination diffusion device for providing illumination having higher intensity than illumination of the light emitting unit to a communication area between wireless image communication devices when underwater bi-directional wireless communication is performed using the wireless image communication devices.

An underwater bi-directional wireless image data communication system includes a wireless image communication device having a comparison processing device for converting an image signal about image data from an image device into an electrical signal, a light emitting unit for receiving the electrical signal from the comparison processing device and converting the electrical signal into an optical signal to output light, and a light receiving unit for receiving an external optical signal and converting the external optical signal into an electrical signal to be output as an image, and an illumination diffusion device for providing illumination having higher intensity than illumination of the light emitting unit to a communication area between wireless image communication devices when underwater bi-directional wireless communication is performed using the wireless image communication devices.

Disclosed are a calibration method and apparatus for a coherent light module, and a computer-readable storage medium. The method comprises: obtaining a first and second curve relationship respectively representing a relationship between a power-gain monitoring voltage and optical power of a receiver of the coherent optical module and a relationship between a target setting voltage and the optical power of the receiver in the optical power range of the receiver; determining first optical power based on the first and second curve relationship, which is used for dividing the optical power range of the receiver into two ranges; and determining a calibration mode of the coherent light module based on the first optical power, which comprises: calibrating the coherent light module by using the first curve relationship or the second curve relationship when the optical power of the receiver is in a first range or in a second range.

A pulse oximetry system for reducing the risk of electric shock to a medical patient can include physiological sensors, at least one of which has a light emitter that can impinge light on body tissue of a living patient and a detector responsive to the light after attenuation by the body tissue. The detector can generate a signal indicative of a physiological characteristic of the living patient. The pulse oximetry system may also include a splitter cable that can connect the physiological sensors to a physiological monitor. The splitter cable may have a plurality of cable sections each including one or more electrical conductors that can interface with one of the physiological sensors. One or more decoupling circuits may be disposed in the splitter cable, which can be in communication with selected ones of the electrical conductors. The one or more decoupling circuits can electrically decouple the physiological sensors.

A digital isolator can include: an encoding circuit configured to receive an input digital signal, and to generate an encoded signal according to the input digital signal; an isolation element having a primary winding, a first secondary winding, and a second secondary winding; a differential circuit configured to receive first and second differential signals, and to generate a difference signal according to the first and second differential signals; and a decoding circuit coupled with the differential circuit, and being configured to receive the difference signal, and to generate a target digital signal after decoding.