High Resolution Optical Displacement Measurements of a Piezo Scanner
In precision positioning systems, errors in step size and repeatability, and vibration are inevitable. Understanding the real behavior of the system allows users to optimize performance and understand limitations. This application note employs the PicoScale Interferometer for the reference characterization of a stick-slip piezo translation stage. A closed-loop translation stage with a Metirio optical encoder is programmed by the SmarAct MCS2 positioning system to execute motion sequences of 1 nm and 2 nm steps. The PicoScale Interferometer is aligned to a mirror mounted atop the stage to measure displacement. The data collected demonstrates the accuracy of the step size, along with vibration and repeatability metrics, providing crucial insights into the performance and reliability of high-precision positioning systems.
Closed-loop Positioning of a Sample with Interferometric Precision
Accurate positioning of a sample is one of the core challenges in today’s high-precision manufacturing and research. The standard approach is to control the position using a high precision positioning system with integrated position feedback. However, the sample can be mounted quite far away from the integrated sensor, so that possible drifts cannot be controlled with the desired accuracy. The PICOSCALE Interferometer can be used to measure at (or at least very close to) the point of interest (POI). It uses an infrared laser beam which is reflected off a target surface to create an interference pattern. This pattern is evaluated and contains the information on the target’s displacement. As the resolution and accuracy is typically far beyond that of linear encoders that use periodic patterns on glass scales, positioning of samples can be brought to a new level of precision.
Straightness Measurements of Translational Stages
In this application note, straightness measurement of a translation stage is demonstrated. As compact and light targets such as thin mirrors can be used, the stages can be characterized without the need of high loads, which may deteriorate the sample unnescessarily. The PICOSCALE Interferometer is a versatile and easy to-use interferometric displacement sensor with three measurement channels. Utilizing the pre-aligned assembly for angular measurements and the software module Calcualtion System, real-time processing (without the need of a user PC to perform these calculations) of the PICOSCALE's position data is performed, extracting pitch and yaw with nrad resolution.
Measurement of Radial Runout and Wobble
In this application note, the PICOSCALE Interferometer is used to measure radial run-out and wobble on a stainless-steel cylinder. This mimics the techniques used in high precision engineering and synchrotron end-stations. Accurate measurement of these parameters is crucial for ensuring the quality of workpieces and the precision of sample positioning in tomography of crystal structures. The setup includes a polished stainless-steel cylinder mounted on a SmarAct XY-stage and rotary stage. Three line-focusing sensor heads are used to measure directly on the cylinder, two at the same height measuring eccentricity, with a third positioned higher to measure wobble. The cylinder is rotated in small increments, and the relative displacements are recorded at each angle. The results demonstrate the PICOSCALE Interferometer's capability to accurately track eccentric movements and provide precise measurements of radial run-out and wobble, essential for high precision applications.
Single Point Vibration Analysis
This application note details the use of SmarAct’s PICOSCALE Interferometer for single point vibration analysis with sub-atomic resolution. For fundamental materials research and development, high resolution and low noise allow for better characterization of samples. A confocal sensor head and built in FFT functionality are tested here to measure the thermal spectrum, and excited resonance of a tungsten cantilever.
These techniques are expanded upon with the PICOSCALE Vibrometer, allowing full modal analyses of small samples.
Additional Application Notes
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Displacement Measurements with Low Output Power Using an Optical Switch214.6 KiB
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Testing a Drone Motor with Single Point Vibrometry600.8 KiB
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PICOSCALE Interferometer with chopped measurement beam799.8 KiB
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Thermal Expansion Coefficient of Invar and Long-Term Stability215.2 KiB
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Sound recording with a glass window694.3 KiB
Specification Sheets
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Specification Sheet - PICOSCALE Interferometer V2.11.5 MiB
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Specification Sheet - PICOSCALE Breakout Box V2995.5 KiB
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Specification Sheet - PICOSCALE Breakout Box V2 Interface170.6 KiB
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Specification Sheet - PICOSCALE Sensor Head Type C01367.4 KiB
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Specification Sheet - PICOSCALE Sensor Head Type F01361.5 KiB
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Specification Sheet - PICOSCALE Sensor Head Type C03335.9 KiB
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Specification Sheet - PICOSCALE Sensor Head Type C04345.8 KiB
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Specification Sheet - PICOSCALE Sensor Head Type L01341.9 KiB
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Specification Sheet - PICOSCALE Environmental Module115.6 KiB
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Specification Sheet - PICOSCALE Differential Sensor Head Assembly647.5 KiB
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Specification Sheet - PICOSCALE Sensor Head Assembly Based on C03 Heads563.7 KiB
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Specification Sheet - PICOSCALE Sensor Head Assembly Based on C01 Heads388.4 KiB
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Specification Sheet - PICOSCALE Sensor Head Manual Alignment Mount (MAM)148.4 KiB
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Specification Sheet - Corner-cube retro-reflectors177.3 KiB