Analysis of static coded aperture imaging spectrometer

Abstract

Scanning and interference imaging spectrometer are widely used in earth observing, microscope imaging, etc. Motion mechanisms are utilized in all these simple imaging spectrometers, which make the system big, expensive and unstable. A novel static non-imaging spectrometer is introduced specifically. 2D (two-dimension) static multi-channel spectral measurement is realized in this spectrometer, utilizing 2D hadamard matrix code mask and 2D detector. The hadamard matrix is different from traditional S circular code. The orthogonal property of hadamard matrix is utilized, and with special transform negative codes in hadamard matrix are also realized. Basing on this non-imaging spectrometer static imaging spectrometer is developed. First 2D imaging spectrometer can be divided into many 1D ones which work independently. The 1D imaging spectrometer is obtained with position information added into the hadamard coding system in dispersive direction. To get 2D imaging spectrometer, extend the coded aperture: put some masks together in non-dispersive direction. According to this model, the spectrum of an image instead of a slit can be estimated at one time. The optical system is designed to simulate the imaging spectrometer. Compared to the simple scanning imaging spectrometer the simulated result shows the model's resolution can be compared to simple scanning spectrometer, but the scanning time of simple scanning imaging spectrometer is about 3 times of our simulation. At last some implementation issues are mentioned.