Recently, a research team led by Prof. XIONG Wei from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences proposed a high dynamic range spatial heterodyne one-dimensional imaging spectroscopy based on a digital micromirror device (HD-SHIS) in response to the low dynamic range of spatial heterodyne imaging spectroscopy (SHIS).
The related results were published in Optics Express.
The SHIS is capable of simultaneously acquiring hyperspectral information in different fields of view (FOVs) and is suitable for the simultaneous acquisition of vertical profiles of the middle and upper atmosphere in the limb detection mode. However, the dynamic range of SHIS is limited by the performance of the detectors.
In this study, researchers proposed HD-SHIS to eliminate dependence on the array detector. This new technique controled the exposure time of each part of view by adjusting the flip time of the micromirror on a digital micromirror device (DMD). This allowed the simultaneous detection of strong and weak signals.
At the same time, HD-SHIS utilized the DMD to realize the Hadamard modulation of the interferometric data, which boots the signal quality for weak light. They built a prototype of the HD-SHIS system and tested it, achieving a significant improvement in dynamic range by 48 dB using an 8-bit DMD.
The HD-SHIS proposed in this research effectively improves the dynamic range in hyperspectral imaging. It can also be used in other interferometric spectrometers, offering significant scientific and practical benefits.
Fig. 1. HD-SHIS verification experiment site (Image by WANG Qiansheng)
Fig. 2. Interferograms and spectral curves of strong and weak targets with high dynamic range detected by HD-SHIS (Image by WANG Qiansheng)