Development of a scanning head for laser Doppler vibrometry (LDV) using dual optical wedges
journal contributionposted on 29.01.2014, 09:52 by Steve RothbergSteve Rothberg, Mario Tirabassi
A new laser Doppler vibrometry scanning head is proposed based on a pair of rotating optical wedges. A comprehensive mathematical model is developed and used to demonstrate how the wedges can be configured to scan point-by-point, in a line, in a circle, and in a combination of the two such that a straight line scan could be performed on a structure during rotation. Inevitable misalignments are incorporated into the model and considered quantitatively for the circular tracking application. Certain advantages are apparent over systems based on dual mirrors and a Dove prism in terms of lower apparent velocities at low rotation orders. A scanning head design for the circular tracking application is presented, together with experimental data showing good agreement between predicted and measured apparent velocities caused by misalignments.
This work was supported by the Engineering and Physical Sciences Research Council [EPSRC studentship].
- Mechanical, Electrical and Manufacturing Engineering