Laser 2000



Polarimeter (PMI)

The PMI Polarimeter is a compact liquid crystal-based system which determines the polarisation of incoming light or quantifies the rotation of optically active substances. It comes with convenient computer controls that can accurately measure polarisation with a ≤ 1% accuracy and can measure Stokes Parameters 10 times per second. The polarimeter is made to be simple to use, even for those with limited polarisation knowledge.

Key features:
  • Compact
  • Patented Liquid Crystal-based design – No moving parts therefore minimal vibrations and wear
  • Broad wavelength ranges – Visible and near infrared versions
  • Fibre and free space versions
  • Simple to use
  • White papers and application notes from the knowledgeable staff at Meadowlark Optics are readily available


Two wavelength ranges available – broader ranges than others on the market:
  • 450 – 1100 nm
  • 900 – 1700 nm


  • Ellipsometry
  • Polarisation control
  • Polarisation analysis
  • Eigenstate Calibration


Meadowlark’s user-friendly Polarimeters provide high accuracy and reliability in an easy to use instrument, suitable for manufacturing and laboratory applications.

The Meadowlark Optics system contains no spinning waveplates, motors, or other moving parts so there is minimal wear and vibrations. Patented algorithms provide high accuracy and calibration versatility.


Eigenstate Calibration Set (ECS) – Calibration accessory for PMI Series polarimeter

The available Eigenstate Calibration Sets (ECS) allow users to re-calibrate the Polarimeter in ~5 minutes and are available in monochromatic or broadband configurations.

The Eigenstate Calibration Set is a tool which produces six polarisation eigenstates: linear polarised light at angles of 0, 90, +45, -45 degrees as well as circular right-handed and circular left-handed polarised light.

These states are created by using a precision dichroic linear polariser in a black housing and a precision quarter waveplate in a blue housing. The housings are CNC machined so that the accuracy of the angles is better than 1 arc minute. Pins on the housings mate to a v-groove and a flat groove in a quasi-kinematic fashion, while magnets provide holding force. This scheme facilitates precise, simple and fast indexing of the polarisation eigenstates.

Large arrows on the housing indicate the transmission axis of the polariser and the fast axis of the waveplates for ease of use.

Absolute Degree of Polarization Accuracy

≤ 1%

Measurement Frequency

10 Hz


0.001 of a Stokes Parameter

Maximum Operating Temperature


Optical Head Dimensions

2.83 x 1.75 x 1.75 in.

Minimum Optical Power to maintain accuracy (sensitivity can be increased to 1 mW by special request)

10 µW

Input Aperture

2 mm

Specifications for monochromatic eigenstate calibration set
Retardence Accuracy λ/350
Thickness 0.79 ± 0.015 in (20.16 ± 0.38 mm)
Clear Aperture 0.32 in (8.13 mm)
Specifications for broadband eigenstate calibration set
Wavelength Range – VIS 450 – 800 nm
Wavelength Range – NIR 690 – 1200 nm
Wavelength Range – IR 1100 – 2000 nm
Retardence Accuracy λ/200
Thickness 1.10 ± 0.02 in (27.94 ± 0.51 mm)
Clear Aperture 0.197 in (5.0 mm)
Eigenstate Calibration Set

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Ask the Expert

If you’re interested in the products shown here, or have questions about something you can’t find on our website, please get in touch through the form below.

Our knowledgeable sales team will be happy to help. We can normally source exactly what you need, or work with you to come up with custom solutions.

Alternatively, just call +44 (0) 1933 461 666 and ask to speak to the Photonics team.