AP01005 Measurement of Mechanical Vibrations Using a Semiconductor Laser

Abstract

In this research, a system for detection and measuring micromechanical vibrations resulting from electric motors using a diode-pumped solid state (DPSS) laser was designed and implemented. The operating principle of this technology is based on directly modulating the semiconductor laser with the electrical signals generated by the mechanical vibrations and then detecting the light beam carrying these information signals, represented by the frequencies of the mechanical vibrations. Using an electrical signal analyzer these signals are displayed and their frequencies are calculated. Both the vibration frequency and amplitude variations with rotor speed are included in the measurements. The data clearly show that 1.5 I_th was the optimal operating current value, and the waveform of vibration underwent noticeable alterations that allowing the detection of subtle vibration details.