Characteristics of lateral-shearing nulling interferometry by use of double Fresnel rhombs

Abstract

Nulling interferometer for directly imaging exoplanets with a segmented-mirror telescope is investigated. Lateral shearing interferometry is applied to a segmented-mirror telescope such as the Thirty Meter Telescope. Use of a pair of double Fresnel rhombs in Mach–Zehnder interferometer achieves achromatic nulling and lateral shearing simultaneously. In this paper, computer simulations of the lateral interferometry with the Fresnel rhombs in the near infrared region are carried out to analyze the effects of segmentation errors, tip-tilt errors, amplitude and optical-path difference errors on its nulling performance.