High precision contactless measurement of displacements
For the high precision measurement of displacements, SmarAct provides the PICOSCALE interferometer.
- 3 parallel laser interferometers in one instrument for 3D measurements
- Measurement bandwidth up to 2.5 MHz (10 MHz sample rate) with a resolution down to 1 pm1
- Measurements possible on most materials (plastic, glass, metal and even water)
- Wide range of sensor heads available for different applications and environments (including vacuum and cryogenics)
- Extendable to a complete laboratory measurement and control instrument with optional modules
- Proven performance with 100s of satisfied customers
________
1 When analysing periodic displacements in the frequency domain
Working Principle
All PICOSCALE products are based on a Michelson interferometer which works by splitting a beam of light into two paths using a beam splitter, reflecting the beams off mirrors, and then recombining them to produce an interference pattern. Changes in the optical path length, caused by displacement or refractive index variations, alter the interference fringes, enabling high-precision measurements of picometer position changes.
You can find a more detailed explanation of this principle in our technology section about Michelson Interferometry.
Advantages of Michelson Interferometers

Michelson interferometers offer exceptional precision and reliability by splitting and recombining light to measure smallest displacements, vibrations, and refractive changes with nanometer or sub-nanometer accuracy. Their versatility, non-contact operation, and ability to perform in demanding environments like UHV or cryo-temperature make them indispensable for applications in metrology, optics, and advanced research.
Learn more about the advantages compared to other technologies in this article: Advantages of Michelson interferometers compared to other architectures
Specifications
PICOSCALE Interferometer V2
|
|
---|---|
Resolution and Noise | See Specification Sheet |
Repeatability [nm] | <1 |
Accuracy1 [m/m] |
10-6 |
Long Term Stability2 [nm] | 1, see Application Note |
Max. Data Rate [MHz] | 10 |
Maximum Target Velocity [m/s] | 1 |
Target Reflectivity | 4% - 100% |
Maximum Working Distance [mm] | 5000 |
Absolute Position Estimation | 1% of working distance |
1 due to wavelength accuracy
2 Working distance 20 mm, ambient conditions, measurement bandwidth 1.2 kHz