Laser vibrometry technology
Laser Doppler vibrometry measures surface motion without contact. VIPICO combines single-point instruments, automated scanning, synchronized acquisition and structural-dynamics analysis to support vibration measurement, ODS visualization and modal testing.
Definition
Laser Doppler vibrometry is an optical method for measuring vibration along the laser line of sight. Motion of the target changes the frequency or phase of the reflected light. An interferometer and signal-processing unit convert this optical change into velocity and displacement information. Because no transducer is attached to the surface, the method avoids sensor mass loading and is useful for lightweight, miniature, hot, moving or difficult-to-access structures.
The achievable signal quality depends on optical return, surface condition, incidence angle, working distance, vibration magnitude, frequency range and the test environment. A successful system therefore combines the sensor with appropriate optics, alignment, acquisition, excitation and analysis.
System categories
A single-point instrument measures one selected location at a time. It is appropriate for fixed-point vibration measurement, machinery investigations, integration into test platforms and response acquisition during modal tests.
A scanning system automatically moves the measurement line of sight through a defined point grid, associates every response with its spatial position and supports ODS or modal-shape visualization.
Measurement chain
Target, working distance, frequency range, vibration level, environment and required result.
Sensor, lens, aiming, excitation, reference channels, sampling and scan plan.
Collect response data, monitor optical return, verify coherence and repeat invalid points.
Generate waveforms, spectra, ODS, natural frequencies, damping estimates and mode shapes.
Comparison
| Requirement | Single-point LDV | Scanning LDV |
|---|---|---|
| Number of locations | One selected point or manually repositioned points | Automated sequence of registered measurement points |
| Primary output | Velocity, displacement, waveform and spectrum at the measured point | Spatial response data, ODS and modal-shape visualization |
| Position information | Recorded separately or by the test fixture | Associated with the programmed scan grid and geometry |
| Typical application | Component vibration, fixed-point response, platform integration | Structural modal testing, large grids and multi-point visualization |
| Recommended VIPICO system | PVM-LDV-300 | PVM-100 |
Structural dynamics
Operating deflection shapes visualize the measured motion pattern under a defined operating or excitation condition.
Experimental modal analysis combines controlled excitation and response measurements to identify modal parameters.
Operational modal analysis estimates modal behavior from measured operating responses when input force is not directly available.
Learn more in Non-Contact Modal Testing Workflow and ODS vs OMA vs EMA.
Selection guide
For large-angle automated scanning, remote structures and modal visualization, review the PVM-100 scanning laser vibrometer for modal testing. For fixed-point measurement and system integration, review the PVM-LDV-300 laser Doppler vibrometer.
Technical resources
Optical principle, signal chain and measured quantities.
Field of view, scanning speed, distance and optical trade-offs.
From test objective and scan grid to result validation.
Inputs, assumptions, outputs and application boundaries.
Optical return, angle, distance, environment and sampling.
Curved-surface planning, acquisition and model correlation.
FAQ
It measures motion along the optical line of sight. Depending on the instrument and signal processing, the output can include velocity, displacement, waveform and spectrum.
A single-point instrument measures one selected position. A scanning system automates multiple spatially registered points so that operating deflection shapes or mode shapes can be visualized.
No. It removes sensor mass loading, but optical return, alignment, incidence angle, distance, sampling, excitation and environmental conditions still influence measurement quality.
Yes. A single-point instrument can measure a response or reference location. A scanning system is more efficient when the objective is to acquire a spatial grid and reconstruct ODS or modal shapes.
Send the test object, working distance, frequency range, expected vibration level and required outputs to the VIPICO engineering team.
