Advertisement

Circular Polarization Measurement Using a Tunable Lithium Niobate Fabry-Perot Filter

  • S. K. Mathew
  • A. Bhatnagar
  • C. Debi Prasad
  • A. Ambastha
Part of the Astrophysics and Space Science Library book series (ASSL, volume 243)

Abstract

A solar polarization analyzer based on an electrically tunable Lithium Niobate (LiNbO 3) Fabry-Perot filter (FP) has been designed and fabricated. This instrument is capable of providing near simultaneous photospheric Cal images, circular polarization maps, and chromospheric Hα observations. A variable electro-optic quarter wave retarder, KD*P (Potassium di-Deuterium Phosphate) along with a linear polarizer is used for analyzing the circular polarization of the Zeeman components. To achieve high signal to noise ratios, alarge number of images (maximum 256) are added, and then the difference between the left and the right circularly polarized images is obtained. The difference gives the net circular polarization over a selected area-of-interest on the solar photosphere, which can then be calibrated to obtain the longitudinal magnetic field map.

Key words

Instruments polarimeter Sun activity flares magnetic fields 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Bonaccini D., Stauffer F.: 1990, A&A. 229, 817Google Scholar
  2. Cauzzi G., Smaldone L. A., Balasubramaniam K. S., Keil S. L.: 1993, Solar Phys. 146, 207ADSCrossRefGoogle Scholar
  3. Debi Prasad C., Mathew S. K., Bhatnagar A., Ambastha A.: 1998, Exp. Astro. 8, 2Google Scholar
  4. Jefferies J. J., Mickey D. L.: 1991, ApJ. 372, 694ADSCrossRefGoogle Scholar
  5. Mathew S. K.: 1998, A study of Solar Magnetic and Velocity Fields, Ph.D ThesisGoogle Scholar
  6. Mathew S. K., Bhatnagar A., Debi Prasad C., Ambastha A.: 1998, A&A 133, 285CrossRefGoogle Scholar
  7. Rust D. M., Burton C. H., Leistner A. L.: 1987, Soc. Photo-Opt. Inst. Eng. Conf. Proc. 627 Google Scholar
  8. Scherrer P. H., Bogart R. S., Bush R. I., et al.: 1995, Solar Phys. 162, 129ADSCrossRefGoogle Scholar
  9. Varsik R. C.: 1995, Solar Phys. 161, 207ADSCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 1999

Authors and Affiliations

  • S. K. Mathew
    • 1
  • A. Bhatnagar
    • 1
  • C. Debi Prasad
    • 1
  • A. Ambastha
    • 1
  1. 1.Udaipur Solar ObservatoryUdaipurIndia

Personalised recommendations