A 100 μm range linear actuator with picometer resolution, subnanometer accuracy and submicroradian tip-tilt error for the characterization of measuring instruments at the nanoscale

We will present the realization and the characterization of a Picometer Reference Actuator (PRA), a metrological instrument based on a precision linear actuator capable of 100 μm range with subnanometer accuracy, picometer resolution, and submicroradian tip-tilt pointing control. The PRA relies on an integrated multiple reflection homodyne interferometer as a high resolution and accurate internal reference, on a multiple reflection based angle sensor, for the active control of the movement straightness, and on a versatile mirrors configuration to transfer the metrological traceability to an external device. The PRA can be used for critical experiments at the nanoscale as an ultra-precise actuator itself, or as a reference actuator to calibrate displacement sensors. In particular, it has been specially designed to characterize the nonlinearities of high-resolution interferometers at the picometer scale. As an application example, we report the characterization of a heterodyne interferometer in turn dedicated to the calibration of piezo-capacitive actuators.