3 results about "Length wave" patented technology

Beam steering devices such as optical phased arrays (OPAs) are key components in applications of solid-state LIDAR and wireless communication. Conventional single-layer OPAs suffer from significant energy loss due to substrate leakage from the down-coupling of grating coupler structures. In this disclosure, we have investigated a structure based on a multi-layer Si3N4 / SiO2 platform that can form a 3D OPA to efficiently emit light from the edge of the device, end-fire the 2D converging out-coupled beam to air. Numerically demonstrated is the high efficiency and wide horizontal beam steering, also discussed are the effects of vertical crosstalk, delay length, number of waveguide layers, and manufacturing feasibility.

This application discloses a method, system, and medium for locating faults at both ends of a transmission line based on the temperature variation characteristics of the transmission line. It belongs to the field of fault location technology for power system transmission lines. The method includes: acquiring the real-time temperature of the transmission line, fixed design parameters, and the arrival time of the fault traveling wave at both ends; determining the corrected line length based on the fixed design parameters and real-time temperature, according to the thermal expansion and contraction relationship of the conductor; determining the inductance and capacitance per unit length based on the real-time temperature and transmission line theory, and determining the corrected traveling wave velocity based on the relationship between wave velocity and distributed parameters; and determining the distance to the fault point based on the principle of two-end traveling wave location, according to the corrected line length, wave velocity, and arrival time of the traveling wave. By implementing this application, the problem of mismatch between the location parameters and the actual physical state caused by parameter fixation in the traditional two-end traveling wave location method can be solved, thus improving the accuracy of fault location.

To provide an optical interference circuit which is applied to a system for transmitting and frequency-converting frequency reference light and can transmit each of a plurality of frequencies of the frequency reference light while maintaining high frequency accuracy.SOLUTION: An optical interference circuit according to the present invention includes a waveguide circuit unit in which an optical waveguide is formed on a substrate, and a frequency conversion unit that converts a frequency of frequency reference light, in which the waveguide circuit unit further includes a reproduction reference light input port, a frequency reference light input / output port, a transmission path fiber input / output port, a first coupler, a frequency selective reflection unit, a frequency synchronization detection circuit, a first detection light output port, a transmission path length fluctuation detection circuit, and a second detection light output port, and the frequency synchronization detection circuit further includes one second coupler. The transmission line length fluctuation detection circuit further includes one third coupler and one fourth coupler connected to the third coupler.SELECTED DRAWING: Figure 4