Laser Doppler vibrometer at 1064nm

Laser Doppler Vibrometers (LDV) have garnered widespread attention and application across various fields due to their high-precision non-contact measurement capabilities. This study employs a single-frequency laser at a near-infrared wavelength of 1064nm as the light source and constructs an external heterodyne laser interferometer system based on a Mach-Zehnder interferometer. By modulating the reference light with a 73 MHz acousto-optic modulator and causing interference with the measurement light on a photodetector, the vibration signal is extracted using phase-locked loop demodulation technology. In the experimental part, we verified that the constructed LDV system can effectively reproduce the 20Hz to 20kHz sinusoidal electrical signals applied to the vibration target, proving the system's wideband response capability and high sensitivity. In addition, by collecting audio signals played by a speaker and applying noise processing algorithms, clear voice signals were successfully restored from the collected data. This indicates that LDV technology can not only monitor vibrations from low to high frequencies but also effectively recognize voice signals in practical environments. This study explores the application potential of LDV in the field of remote voice monitoring. The research results provide a new perspective for remote voice monitoring and recognition and offer valuable references for the development and practical application of related technologies and practices.