Less than 1nm scanner bow during a 60µm scan line.

Piezo Stage Sensors for Closed-loop Control

A position sensor is necessary to provide closed-loop control for the nanopositioning system.  There are different types of sensors that can be used to provide the measuring feedback to eliminate inherent issues with piezos such as non-linearity and hysteresis.  Three common types of sensors include capacitive, strain gauge, and LVDT.  Each has advantages for certain […]

The application of notch filters

Quadrature Interferometer Sensor Integration for Closed-loop Feedback

This article provides data that demonstrate the capability of nPoint controllers to integrate with quadrature sensor signals for closed-loop feedback. In some applications using an external sensor such as an interferometer can be essential in order to compensate for drift or maintain position in an entire system.  Adding this capability eliminates the need for internal […]