Physics:Image mapping spectrometer

The Image Mapping Spectrometer (IMS) is a snapshot hyperspectral camera that is developed for spectral imaging applications. The IMS was invented by three researchers (Dr. Tomasz Tkaczyk, Dr. Robert Kester and Dr. Liang Gao) at Rice University, Houston, TX.

Prior to the invention of the IMS, most hyperspectral cameras require scanning to acquire a 3D (x, y, lambda) data cube, either in the spatial domain, e.g. hyperspectral confocal microscope, or in the spectral domain, e.g., liquid crystal tunable filters or acoustic optic tunable filter. The scanning mechanism cause a serious trade-off between system throughput and scanning speed. The scanning-based hyperspectral imagers are not suitable for dynamic imaging applications which require high temporal resolution.

The IMS overcomes this limitation by acquiring spatial and spectral information simultaneously within a single integration event. The parallel acquisition is achieved by utilizing a custom-fabricated component - termed image mapper - as a field remapping unit in the IMS. The image mapper consists of hundreds of mirror facets, the size of which is around 70 micrometres. Each mirror facet has a two-dimensional tilt angles, reflecting light towards x direction and y direction. The image mapper cut the field into strips and create blank regions between adjacent image strips on the CCD camera due to the tilt angle difference of mirror facs. The image strips are then dispersed into these created blanked regions by an array and prisms and reimaging lenses. In this way, each pixel on the CCD camera is encoded with unique spatial and spectral information of the sample. By implementing a simple image remapping algorithm, a (x, y, lambda) datacube is measured.

The IMS has widespread applications in biomedical imaging, chemical imaging, and remote sensing. The IMS technology is now commercialized by Rebellion Photonics, inc.