[Sander, Ian, and Daniel]

The three of us set up a Michelson Interferometer to test the Noliac NAC2125-H08 (Ring Piezo) with 1550 nm laser light. See attached photo. The alignment was optimized to maximize the contrast.

The piezo is rated for 200 V and the MDT693B (Thorlabs Open-Loop Piezo Controllers) is rated for 150 V, but we decided to linearly sweep the data from 0 V to 150 V over 20 s. We saw the interferometer go through 8 fringes, exactly what we expect.

Free stroke = 12.6 μm , so there is a length change of 63 nm/V. Applying 100 V gives 6300 nm. A fringe is every 775 nm (the path length changes 2x the piezo change). Fringes = length change / (length/fringe) = 8.1 fringes, pretty much exactly what we observe. See attached graph and data.