Design of a spectrum-folded Hadamard transform spectrometer in near-infrared band

A spectrum-folded Hadamard Transform spectrometer in near-infrared band has been proposed and designed to widen the spectral range of measurement as well as to improve the spectral resolution. The full spectral region of 800 nm to 2000 nm is divided into two bands of 800 nm to 1400 nm and 1400 nm to 2000 nm and dispersed by two sub-gratings. The optimal incident angles of 12.6° and 6.7° respectively for two sub-gratings are chosen to achieve the highest diffraction efficiency. The results show that the spectral resolution of the system is better than 6 nm. The stray light from sub-gratings and DMD are suppressed to minimize the effect on the measurement results.