Technology for Polarization Measurement

250 AT Birefringence Measurement System

The 250AT is the ‘Step-up’ model of the Exicor® birefringence measurement system family of products.  This model was developed to replace the obsolete Exicor 350AT and is widely used for lighter weight but larger samples such as plastic films.  Built on the Exicor 150AT frame, this system incorporates a larger scan area (up to 250mm x 250mm) while maintaining the desk top nature of the Exicor 150AT system.  This is also the system most customers select when they choose the Exicor ATS (spectroscopic measurements) option for studying birefringence at different wavelengths.  The larger stage size also allows for loading multiple small parts on the stage and in conjunction with the optional Exicor Macro+ software to execute automated routines to scan each part individually.  The user can begin the routine and let it run for multiple shifts, overnight or even longer (depending on the application) without having to intervene.

With two measurement range options available to choose from (High Sensitivity and Extended Range),  the system is well suited to address the demanding requirements of your larger light weight samples.  The optional high speed scanning package makes high spatial resolution scans (<1mm grid spacing) practical.


  • 250mm Automated XY stage
  • 2D and 3D graphical representation of birefringence parameters
  • Large and Flexible stage platform design for adding custom parts holders or process aids
  • Advanced data analysis features included standard in user interface



Retardation Range: 0.005 to 300+ nm
Retardation Resolution / Repeatability1, 2: 0.001 nm / ± 0.015 nm
Angular Resolution / Repeatability1: 0.01º / ± 0.07º
Measurement Rate / Time3: up to 100pps / sample size dependent
Size: 910 mm (H) x 415 mm (W) x 700 mm (D)
Light Source Wavelength4: Various (632.8 nm standard)
Measurement Spot Diameter5: Between 1 mm and 3 mm native (can be as low as
50 µm)
Modulation Technique / Frequency: PEMLabsTM Photoelastic Modulator / 50 kHz and
50/60 kHz
Demodulation Analysis Technique: Hinds Instruments SignalocTM Lock-in Amplifier or Wave
Form Capture Card
Measurement Units: nm (retardation),° (angle)


1 Typical performance at 5nm retardation

2 Up to 1.5 nm, 1% thereafter

3 Maximum data collection speed. Sample XY scan time dependent on stage movement parameters.

4 Custom wavelengths available

Spot sizes of less that 1mm (native) require optional high resolution detector module


  • Additional Polarization Parameters
  • Hinds Scan in Motion TM (High Speed Scanning)
  • Spectroscopic and RGB measurements
  • Custom wavelengths (VIS, NIR)
  • Manual and automated tilt stages
  • Custom Sample holders
  • Custom Software (UI or DLL)
  • Stress Estimation Calculations

Contact us for more information about the Exicor 250AT and to see how Hinds Instruments works with our customers to provide unsurpassed birefringence measurement metrology.