SmartWLI Compact

White Light interferometer for industrial applications

3D surface sensor optimized for in-line and mobile use requiring high performance in harsh environments with extremely short cycle times.

  • FAST - Cycle times below 1 second possible
  • ROBUST - optimized for inline applications

Operation without vibration dampening possible.


Optical 3D sensor based on white-light interferometry

Robust sensor for inline applications with limited or without vibration dumping

  • piezo drive for sub-nanometer resolution
  • optional mechanical precision axis for extended z-range and cost sensitive projects
  • optional utilization of external positioning systems


  • massive parallel data processing on GPU's
  • exteme fast scanning
  • real time 3D evaluation
  • optimized for steep structures
  • integrated data quality parameter for sample optimized filtering processes

Single objectives

  • manual exchangeable
  • magnifications from 2.5x ... 100x

smartvis3D dll

  • easy integration of all sensor functions into external application
  • alternative simplified communication via IO module
  • customized communication modules on request
  • support various exchange data formats
  • optional evaluation processes using Mountains Map or other third party software packages


Vertical Scanning Technology

Vertical scanning principle

  • The Piezo lifts the objective in z axis and the camera grabs the images in equidistant steps
  • The image stack contains the information to calculate the profile data from the surface
  • Each indipendent pixel will show a so named correlogram and the maximum sinus like light variation indicates a defined z-distance from the objective
Interferometry, Interference Objectives, Principles

Exchangeable Interference Objectives

  • Mirau objectives are used for higher magnification (10x, 20x, 50x, 100x)
  • Michelson objectives are used for lower magnification (2.5x, 5x)
  • The objectives are exchangeable and this feature can be used to adapt the system to the necessary field of view and resolution
  • Interference pattern will be pictured if object and reference beam have the same length
  • The interferometry provides an extreme height resolution of 0.1 nm for all objectives (in contrary to other principles as confocal microscopy and focus variation)

Technical Features


smartWLI compact
Measurement Technique   White-light interferometry
Dimension   218 x 58 x 105 mm 
Sensor weight   app. 2kg
Power Supply   100 to 240 VAC, 50/60 Hz

Vertical scanning
Phase shifting
Combined method

System Software   smartVis 3D / Speedytec on GPU /real time 3D calculation
Evaluation Software   Mountains Map with GBS programmed extensions
Piezo Scanner   Precision piezo drive with capacitive gauge control
up to 400 um z-range
VSI: 1 nm z-resolution
PSI: 0.1 nm z-resolution
Precision Axis   Mechanical precision axis
up to 5mm z-range
VSI: 10nm z-resolution


high speed camera 1900 x 1200 pixel / 170Hz
Scanning Speed    up to 250 um/s - full camera resolution 
Magnification   2.5x 5x 10x 20x 50x 100x
FOV / mm2    7.3 x 4.6 3.7 x 2.3   1.8 x 1.2  0.91 x 0.58  0.37 x 0.23 0.18 x 0.12 
Spacing /um   3.8 1.9 0.96 0.48 0.19 0.1
WD /mm   10.3 9.3 7.4 4.7 3.4 2


high resolution camera / 86Hz
Scanning Speed    up to 120 um/s - full camera resolution 
Magnification   2.5x 5x 10x 20x 50x 100x
FOV / mm2    6.8 x 5.7 3.4 x 2.8   1.7 x 1.4  0.85 x 0.71  0.34 x 0.28 0.17 x 0.14 
Spacing /um   2.8 1.4 0.69 0.35 0.14 0.07
WD /mm   10.3 9.3 7.4 4.7 3.4 2