Perspective: Spectral imaging, multispectral imaging and hyperspectral imaging
Multispectral imaging evaluates a field of view (FOV) with non-contiguous wavelengths. Instruments are often based on a liquid crystal tunable filter (LCTF) or an acousto-optic tunable filters (AOTF) in front of a scientific matrix-array camera. Typically, low spectral resolution with up to 100 wavelength data points.
Hyperspectral imaging: is a hardware and software system in which spectra presented by objects in a FOV are correlated to spectra in a reference library. Modern hyperspectral imaging systems acquire hundreds to thousands of spectra simultaneously with each spectrum presenting many hundreds of wavelength data points.
Hyperspectral imaging microscopy
Hyperspectral imaging was originally developed for remote Earth sensing in the mid-1970s. Since then advances in computer technology enabled innovative spectroscopic hardware designs that reduced weight and improved sensitivity.
In 1996 LightForm utilized these advances to pioneer hyperspectral imaging microscopy for biological and medical applications. The goal required that the instrument be sensitive enough to handle low light levels and compact enough to easily mount as an accessory on almost any microscope, without external support.
The solution was found by discarding diffraction grating solutions in favor of a prism-based system originally developed by The Aerospace Corporation* for remote sensing. After redesign the PARISS imaging spectrograph was ideal for use as a microscope accessory.
A unique prism increases hyperspectral imaging microscopy sensitivity
The curved sides add optical power to the system to deliver near aberration-free imaging with 90% efficiency from 365 to 920-nm. The net result is a significant improvement in signal to noise ratio (S/N) when compared to grating solutions. Enhanced sensitivity extended into the near IR where detectors and visible diffraction gratings are at their weakest.
The PARISS imaging spectrograph was then developed into the PARISS hyperspectral microscope
Custom hyperspectral software