Description: An extension to NIR spectroscopy, to enable analysis of the contents of an heterogeneous object

Recommended Product: Opotek Opolette

Hyperspectral or spectral imaging is a relatively new technique used to simultaneously acquire the entire spectrum reflected from a large number of points across a sample's surface.

This information is then used to identify and map the distribution of the components from which the sample is made.

The technique is becoming more widely used in pharmaceutical, medical, forensics and chemical process applications.

The HySPEC system from Opotek utilises a tunable OPO laser system as its source, rather than a broadband white-light source and a series of filters. In this arrangement, the tunable OPO laser system scans through the NIR wavelength range, and the light is delivered to the target via fibre-optic bundles. The reflected light is then collected via an IR camera and the hyperspectral cube recorded.

Hyspec layout diagram and principle of operation

Systems that use a broadband white-light source have limitations such as generating heat which can damage the sample, are slow to gather data, and have a limited spectral range and field of view (FOV).

Hyspec large field of view

Replacing the light source with a tunable OPO laser source provides several advantages:

 
  • Macro & micro field of view
  • Higher spectral resolution
  • Wider spectral range
  • Flexible system design
  • Faster Data Acquisition
  • No thermal effects

The tunable OPO laser system offers a wide, continuous tuning range (UV-VIS-NIR) with a short pulse width, high peak power and low average power.

The system works in a fast scan mode such that:

Hyspec system from Opotek
  • The data is normalized and calibrated in real time for every frame
  • The signal collected in a single frame is sufficient to analyze the data and there is no need for averaging
  • Therefore, the system can acquire high-resolution, calibrated data in a few seconds

The Hyspec system is designed to have a wavelength range of 440 – 700nm & 850 – 1700nm with a field of view of up to 20cm wide.

Furthermore it has a spectral resolution of <1.5nm over the entire wavelength range, operating at a speed of 10 wavelengths per second.

The short 5-ns pulse widths, rapid wavelength tunability, high peak power, and low average power enables high-sensitivity spectral imaging measurements to be made on samples (including human subjects) that would not be able to withstand the high intensities of conventional incandescent light sources.
Model Wavelength range Bandwidth Camera Pixels
VIR 440 - 700nm & 850 - 1650nm 0.5nm in the visible 1.5nm at 1650nm VIS GaAs 256 x 320 30µm x 30µm
NIR S 900 - 1700nm <1.5 nm at 1700 nm InGaAs 256 x 320 30µm x 30µm
NIR L 1450 - 2500nm <3 nm at 2500 nm InSb 256 x 320 30µm x 30µm
Hyspec component map, classification results and spectra of components