Abstract: Disclosed are a device and system for detecting ground subsidence by using a LiDAR technology. The system for detecting ground subsidence, which detects whether the ground has subsided within an area where the subsidence of the ground will be examined includes at least two reflection units installed in a structure disposed within an area where the subsidence of a ground will be examined and each configured to reflect light incident thereon, and a LiDAR device disposed within a preset radius from the structure and configured to detect whether the ground has subsided and the extent of the ground subsidence based on a distance difference between the LiDAR device and each of the reflection units.

Abstract: Disclosed is a Doppler LiDAR apparatus using a plurality of wavelength lasers. The Doppler LiDAR apparatus may include a plurality of light sources each configured to output light for detecting the speed of a target and the directivity of a moving target, an optical system configured to adjust the path or state of light to be output to the outside or reflected light that is reflected by the target, an interferometer configured to make the light that is output by any one of the plurality of light sources and the reflected light that has passed through the optical system interfere with each other, and a detection unit configured to detect information on the distance and speed of the target by receiving the light that has been subjected to interference in the interferometer.

Abstract: Disclosed is a multi-channel coherent LiDAR apparatus. The LiDAR apparatus includes a plurality of analog-to-digital converts (ADCs) each configured to receive reflected light reflected by a target and to convert the reflected light into a digital signal, one or more modulation units configured to receive the digital signals that have passed through some or all of the ADCs and channel signals having different frequencies or types and to modulate the digital signals, an adder configured to integrate the signals that have been modulated and received from the modulation units, a fast Fourier transform (FFT) unit configured to convert one signal integrated by the adder into a signal in a frequency domain, and a detection unit configured to detect the information on the distance of the target based on the signal converted into the signal in the frequency domain through the FFT unit.

Abstract: A LiDAR apparatus may include a first light source configured to output light for detecting a distance up to a target, a second light source configured to output light for detecting the speed of the target, a third light source configured to output light for detecting the directivity of the target moving, a light combination unit configured to combine the pieces of light radiated by the first to third light sources, an optical system configured to adjust the path or state of light to be output to the outside or reflected light reflected by the target, an interferometer configured to receive the combined light and the reflected light and to make the combined light and the reflected light interfere with each other, and a detection unit configured to detect information on the distance and speed of the target by receiving the light subjected to the interference.

Abstract: A laser generation apparatus includes a light source making oscillate a laser having a frequency based on the amount of current applied thereto, a splitter ramifying a laser incident thereon at a preset ratio, an interference system receiving the ramified laser, generating an interference signal by ramifying a laser incident thereon, and measuring the phase of a laser oscillated, a temperature adjustment unit uniformly maintaining a temperature of a part of the interference system, an error integrator receiving a signal that has undergone the interference system and accumulating a phase error occurred, a phase error detection unit detecting a phase difference between the signal of the error integrator and an offset current value, a driving driver applying a current to the light source, and a control unit controlling an operation of each component and controlling the driving driver based on results of the detection of the phase error detection unit.