Modular assembly provides significant flexibility for any laboratory.
The PARISS hyperspectral imaging system mounted on a research microscope
PARISS®: Prism And Mirror Imaging Spectroscopy System
Hyperspectral and Multi-Spectral Imaging Methodologies
Spectra presented by objects in a FOV are correlated to spectra in a reference library. An imaging spectrometer acquires spatially resolved spectra with hundreds of contiguous wavelengths providing hundreds of wavelength data points per spectrum.
Spectral imaging instruments almost always use a diffraction grating or a prism as the wavelength dispersive element.
LightForm designs unique hyperspectral imaging systems for use in the laboratory and the field.
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 filter (AOTF) in front of a scientific matrix-array camera. These devises often operate with low spectral resolution with up to 100 wavelength data points.
Hyperspectral Imaging Instruments
Hyperspectral imaging, also referred to as imaging spectroscopy, 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 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. Essentially a laboratory solution based on satellite remote sensing technology .
A Unique Prism With Curved Sides Dramatically Increases hyperspectral Instrument Sensitivity
In order to increase sensitivity diffraction grating designs were discarded 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.
The final design resulted in a prism with curved sides that was named using an acronym “PARISS®” (Prism and Reflector Imaging Spectroscopy System”).
The curved sides add optical power 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 diffraction grating solutions. Enhanced sensitivity extends into the near IR where detectors and visible diffraction gratings are at their lowest efficiency. See here for details.
Custom software shows the location and distribution of all, or selected, spectral-objects on a spectral topographical map.
Unlike most hyperspectral software packages PARISS utilizes Spectral Waveform Cross Correlation Analysis (SWCCA) in order to best extract signal buried in noise and increase sensitivity. This translates into faster acquisition time even in a low S/N environment.
Hyperspectral Imaging fundamentals
Hyperspectral imaging and “spectral imaging” basics
Following advances in computing power and instrument hardware, hyperspectral imaging and spectral imaging have merged. The goal is to identify and map the location of target objects within a heterogeneous field-of-view. The spectra of target objects form a reference spectral library of pseudo-color coded spectra. Spectra presented by objects in the field-of-view that correlate with reference spectra form a color-coded hyperspectral image. Areas within the field-of-view that fail to correlate with a library spectrum are colored black.
Hyperspectral imaging applications
When used close to a field-of-view, hyperspectral imaging applications include the detection of microplastics and cyanobacteria, medical diagnostics, pathology, nanoparticle characterization, environmental pollution, the analysis of advanced material coatings and industrial quality control (QC).
Hyperspectral imaging spectroscopy
Spectroscopic methods include %reflection, absorption, darkfield scatter, fluorescence, luminescence, and photoluminescence.
What is the difference between hyperspectral vs. multispectral imaging?
A multispectral image is characterized sequentially through a series of non-contiguous 5 to 20-nm wavelength bandpass filters. Multispectral cameras do not use a prism or a diffraction grating; consequently, the number of wavelength bandpass data points are limited. Spectra accumulate in the pixels of an area array CMOS or CCD camera. A hyperspectral image characterizes an unlimited field-of-view with many hundreds of contiguous wavelength data points. The spectral resolution is high, ranging from 1-nm (such as that delivered by the PARISS system) to a maximum of 10-nm. All wavelengths are acquired simultaneously through a prism or diffraction grating imaging spectrometer. Often referred to as a “push-broom” system, an unlimited field-of-view translates under the spectrometer and stops when the user ends the scan.
Click herefor a performance comparison between a prism and a diffraction grating.
How PARISS Analytical Hyperspectral Imaging Works
How PARISS Hyperspectral Wavelength Dispersive Imaging Works