Stokes Polarimetery

One method of representing light polarization is to use Stokes vectors (I, Q, U, and V). A dual PEM system can be used to measure all four Stokes parameters simultaneously, thus completely characterizing the polarization state of light.

HOW STOKES PARAMETERS ARE MEASURED

I total intensity; proportional to the DC signal
Q linear polarization component at 0° or 90°; PEM2’s 2f frequency
U linear polarization component at 45°; PEM1’s 2f frequency
V circular polarization component; PEM1’s 1f frequency

Q, U, and V can be determined simultaneously at a fast data acquisition speed from the outputs of lock-ins I, II and III, respectively.

APPLICATIONS

Astronomy; light source characterization; MSE diagnostic in Tokamak installations

DUAL PEM CONFIGURATIONS

II/FS20&23; II/FS42&47; I/FS50&55 for UV-Vis
II/ZS37&50 for mid-IR

COMPONENTS

Universal PEM Mount

Signaloc™ 2100 Analog, Dual-Phase Lock-in Amplifier

INSTRUMENTATION

Stokes Polarimeter

PolSNAP^TM Stokes Polarimeter

FURTHER READING

T. C. Oakberg, Application note – Stokes Polarimetry, Hinds Instruments, Inc. (1991).

J. C. Kemp, G. D. Henson, C. T. Steiner and E. R. Powell, “The Optical Polarization of the Sun Measured at a Sensitivity of Parts per Million”, Nature, 326, 270-273 (1987).

H. Povel, et al., “Two-dimensional polarimeter with a charge-coupled device image sensor and a piezoelastic modulator”, Applied Optics, 33, 4254 (1994).

D. Wroblewski and L. L. Lao, “Polarimetery of Motional Stark effect and determination of current profiles in DIII-D” , Rev. Sci. Instrum. 63, 5140 (1992).

Stokes Polarimetry

Stokes Polarimeter Product Bulletin

Contact us for more information on using PEMs in Stokes applications.