Design of a Dual-Channel Mach-Zehnder Lateral Shearing Interferometer for the Large Aperture Static Imaging Spectrometer
FU Qiang1,2, XIANGLI Bin3, Lü Qun-bo3, JING Juan-juan1,2
1. Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China 2. Graduate University of Chinese Academy of Sciences, Beijing 100049, China 3. Academy of Opto-Electronics, Chinese Academy of Sciences, Beijing 100094, China
Abstract：Large aperture static imaging spectrometry (LASIS) is a kind of joint temporally and spatially modulated Fourier transform imaging spectrometry. In such instruments, lateral shearing interferometer is a key element, the most frequently used type of which is the Sagnac interferometer. In this configuration, one half of the light entering the interferometer backtracks and causes a great decrease in energy efficiency. The present paper proposes a modified Mach-Zehnder lateral shearing interferometer structure to tackle this problem. With the ability to produce the same lateral shear, it features the advantage of dual channel output. We present a ray tracing procedure to induce the general expression of the lateral shear as well as analyze the contributions of error sources to the shear accuracy. The results serve as a new idea for the design of large aperture static imaging spectrometers and can be used to instruct the design and optimization of this kind of imaging spectrometer.
