MODULATORS :: APPLICATIONS :: 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 light polarization state.

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

RESOURCES

Stokes Polarimetry Application Note          Dual PEMs for Stokes Polarimetry          PEM Newletter 11:  A PEM based Stokes Polarimeter for Tokamak Plasma Diagnostics

Astronomy; light source characterization; current 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
Universal PEM Mount

OTHER 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, Nature, 326, 270-273 (1987).

H. Povel, et al. Applied Optics, 33, 4254 (1994). 

D. Wroblewski and L. L. Lao, Rev. Sci. Instrum. 63, 5140 (1992).