Analysis of polarization introduced due to the telescope optics of the Thirty Meter Telescope

Ramya Manjunath Anche; Asoke Kumar Sen; Gadiyara Chakrapani Anupama; Kasiviswanathan Sankarasubramanian; Warren Skidmore

doi:10.1117/1.JATIS.4.1.018003

22 January 2018 Analysis of polarization introduced due to the telescope optics of the Thirty Meter Telescope

Ramya Manjunath Anche, Asoke Kumar Sen, Gadiyara Chakrapani Anupama, Kasiviswanathan Sankarasubramanian, Warren Skidmore

Author Affiliations +

Journal of Astronomical Telescopes, Instruments, and Systems, Vol. 4, Issue 1, 018003 (January 2018). https://doi.org/10.1117/1.JATIS.4.1.018003

Abstract

An analytical model has been developed to estimate the polarization effects, such as instrumental polarization (IP), crosstalk (CT), and depolarization, due to the optics of the Thirty Meter Telescope. These are estimated for the unvignetted field-of-view and the wavelengths of interest. The model estimates an IP of 1.26% and a CT of 44% at the Nasmyth focus of the telescope at the wavelength of 0.6 μm at field angle zero with the telescope pointing to zenith. Mueller matrices have been estimated for the primary, secondary, and Nasmyth mirrors. It is found that some of the Mueller matrix elements of the primary and secondary mirrors show a fourfold azimuthal antisymmetry, which indicates that the polarization at the Cassegrain focus is negligible. At the inclined Nasmyth mirror, there is no azimuthal antisymmetry in the matrix elements, and this results in nonzero values for IP and CT, which would negatively impact the polarization measurements at the telescope focus. The averaged Mueller matrix is estimated at the Nasmyth focus at different instrument ports and various zenith angles of the telescope. The variation in the Mueller matrix elements for different coatings is also estimated. The impact of this polarization effect on the science case requirements has been discussed. This analysis will help in achieving precise requirements for future instruments with polarimetric capability.

Citation Download Citation

Ramya Manjunath Anche, Asoke Kumar Sen, Gadiyara Chakrapani Anupama, Kasiviswanathan Sankarasubramanian, and Warren Skidmore "Analysis of polarization introduced due to the telescope optics of the Thirty Meter Telescope," Journal of Astronomical Telescopes, Instruments, and Systems 4(1), 018003 (22 January 2018). https://doi.org/10.1117/1.JATIS.4.1.018003

Received: 10 June 2017; Accepted: 18 December 2017; Published: 22 January 2018

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available