Spatial scanning hyperspectral imaging combining a rotating slit with a Dove prism

Abstract

We present a new concept for spatial scanning hyperspectral imaging. Spatial scanning is one of the main methods used for hyperspectral data acquisition and can provide high spectral resolution over a wide spectral range. However, conventional techniques, such as the whiskbroom and the pushbroom techniques, suffer from the need for relative motion between the target and the imaging system, which increases the complexity on the hardware side and limits the application possibilities. Our new approach combines a rotating slit and a co-rotating Dove prism. The rotating slit scans the target image by selecting one line from the image at each angular position of the slit. The rotating Dove prism is used to synchronously realign the transmitted light from the selected image line with respect to the transmission grating to allow the projection of the diffracted light over the same range of pixel columns of the image sensor to facilitate data acquisition and extraction of spectral information. The new approach enables the spatial scanning of the target image without the need for relative linear motion or the use of additional external equipment and therefore opens the door for more application scenarios.

Hyperspectral Imaging for Clinical Applications

“…Reflected light from a single point (point scanning) or single line (line scanning) is measured via a spectrometer or spectrograph [7,36], respectively. The measured signal shows the light intensity as a function of wavelength, but there is missing spatial information.…”

Compact and ultracompact spectral imagers: technology and applications in biomedical imaging

“…These methods of acquisition are not suitable for bioengineering applications such as surgical guidance or in vivo imaging. 129 To develop spectral imagers that can be compact and usable for live imaging, new techniques in spatial scanning acquisition have been devised to overcome the movement problem. These techniques use microelectronic internal devices such as digital micromirror devices (DMD) 142 and piezoelectric motors 70 , 79 , 143 to move the imaging sensors or optical components.…”

“…Many low-cost and compact systems used prisms 128 – 130 or transmission grating 70 , 85 , 102 , 131 – 133 as the monochromator. The problem was that these systems were prone to artifacts due to misalignments of the optical components 85 .…”

ECORE: A New Fast Automated Quantitative Mineral and Elemental Core Scanner

“…This hypercube was used to define hyperspectral imaging even at the very beginning of remote sensing discussions when area, point, and line-scanning types had not yet been defined [4]. All three hyperspectral imaging techniques are described as such by many sources [3,5,6].…”