Image mapping spectrometer
Encyclopedia
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)datacube, 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 micron
s. 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 a 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.
Hyperspectral imaging
Hyperspectral imaging collects and processes information from across the electromagnetic spectrum. Much as the human eye sees visible light in three bands , spectral imaging divides the spectrum into many more bands...
that is developed for spectral imaging
Spectral imaging
Spectral imaging is a branch of spectroscopy and of photography in which a complete spectrum or some spectral information is collected at every location in an image plane...
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)datacube, either in the spatial domain, e.g. hyperspectral confocal microscope
Confocal microscopy
Confocal microscopy is an optical imaging technique used to increase optical resolution and contrast of a micrograph by using point illumination and a spatial pinhole to eliminate out-of-focus light in specimens that are thicker than the focal plane. It enables the reconstruction of...
, or in the spectral domain, e.g., liquid crystal tunable filters
Liquid crystal tunable filter
Liquid crystal tunable filters are solid-state optical filters that use electronically controlled liquid crystal elements to transmit a selectable wavelength of light and exclude others...
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
Dynamic imaging
Dynamic imaging is the amalgamation of digital imaging, image editing, and workflow automation. It is used to automate the creation of images by zooming, panning, colorize and performing other image processing and color management operations on a copy of a digital master.Dynamic imaging technology...
applications which require high temporal resolution
Temporal resolution
Temporal resolution refers to the precision of a measurement with respect to time. Often there is a tradeoff between temporal resolution of a measurement and its spatial resolution. This trade-off can be attributed to the finite speed of light and the fact that it takes a certain period of time...
.
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 micron
Micron
Micron can refer to:*Micron, a non-SI name for micrometre*Micron , is the measurement used to express the diameter of a wool fibre.*A small curved diacritic mark above some letters, used to indicate shortness, e.g...
s. 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 a 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
Chemical imaging
Chemical imaging is the analytical capability to create a visual image of components distribution from simultaneous measurement of spectra and spatial, time informations....
, and remote sensing
Remote sensing
Remote sensing is the acquisition of information about an object or phenomenon, without making physical contact with the object. In modern usage, the term generally refers to the use of aerial sensor technologies to detect and classify objects on Earth by means of propagated signals Remote sensing...
. The IMS technology is now commercialized by Rebellion Photonics, inc.