Stokes Polarimetry

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

SETUP

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

COMPONENTS

Signaloc 2100 Analog, Dual-Phase Lock-in Amplifier
 

INSTRUMENTATION

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.