Laser Vibration Sensing

Radar-based Mechanical Vibration Sensing for Structural Health Monitoring Applications: A Comparison of Radar Transceiver Measurements at 24GHz and 100GHz

Conventional strategies to measure mechanical vibrations from remote distance are based on Laser-Doppler-vibrometry (LDV). This technique is only rarely used in practical structural health monitoring (SHM) applications, due to the high costs of these devices. Radar technology represents a promising new approach towards in-situ SHM-scenarios with permanently installed sensors, because of the low...

Continuous Scanning Laser Doppler Vibrometry for Synchronized Array Measurements: Applications to Non-contact Sensing of Human Body Vibrations

A Deformed Shape Monitoring Model for Building Structures Based on a 2D Laser Scanner

High-rise buildings subjected to lateral loads such as wind and earthquake loads must be checked not to exceed the limits on the maximum lateral displacement or the maximum inter-story drift ratios. In this paper, a sensing model for deformed shapes of a building structure in motion is presented. The deformed shape sensing model based on a 2D scanner consists of five modules: (1) module for acq...

Eliminating noises contained in sensing signals from a self-mixing laser diode

The paper studied the noise elimination methods for the signals observed from a self-mixing-laser diode (SMLD) based sensing system. The core part of the sensing system consists of a LD, a lens and an external vibrating target. The proposed noise elimination methods are applied on both the simulated and experimental sensing signals. The results presented in the paper show the noise contained in...

Ultrafast Laser-Based Spectroscopy and Sensing: Applications in LIBS, CARS, and THz Spectroscopy

Ultrafast pulsed lasers find application in a range of spectroscopy and sensing techniques including laser induced breakdown spectroscopy (LIBS), coherent Raman spectroscopy, and terahertz (THz) spectroscopy. Whether based on absorption or emission processes, the characteristics of these techniques are heavily influenced by the use of ultrafast pulses in the signal generation process. Depending...