Straightness Measurements of Translational Stages

This application note demonstrates the use of the PICOSCALE Interferometer for straightness measurements of translation stages. The system leverages its three-channel measurement capability, compact sensor heads, and real-time processing to deliver precise characterization without imposing high loads on the test setup.

Problem: Conventional methods for measuring the straightness of translation stages often require the application of high loads, which can degrade the stage's performance and compromise measurement accuracy.

Solution: The PICOSCALE Interferometer provides a non-invasive, precise, and user-friendly method for straightness measurements. Its lightweight sensor heads and real-time processing capabilities enable accurate characterization without the need for additional heavy equipment.

Implementation:

• A lightweight 1-inch mirror is mounted on the translation stage using a custom adapter.
• The PICOSCALE sensor head assembly, comprising three pre-aligned heads, is aligned with the mirror.
• Signals from the sensor heads are processed in real-time by the PICOSCALE Calculation System to compute pitch and yaw values during a 20 mm stage movement.

Result: The measurements revealed a pitch of approximately 140 µrad and a yaw of 80 µrad over a 20 mm stroke. This demonstrates the limited straightness of the stage's bearings and the effectiveness of the PICOSCALE system in detecting and characterizing such deviations.