PARISS® Imaging Spectrograph

The PARISS prism based imaging spectrograph (Model PPIS) enables spatially resolved spectroscopic imaging. 

The PARISS Imaging spectrograph/spectrometer

An imaging spectrograph presents spatially resolved spectra with all acquired wavelengths simultaneously. When used with a spectrum detector such as a CCD or CMOS camera it becomes an imaging spectrometerThe goal is to enable point to point imaging (see Figure 1)

Traditional spectrometers use diffraction gratings in a Czerny Turner geometry (yes, there are others).  Aberrations make it impossible to image a point on the entrance slit as a point on the detector due to significant aberrations.  This problem can be obviated with the use of aspheric optics.

More recently  holographic gratings with aberration correcting properties made spectral imaging feasible. Using a prism with curved sides provides an elegant alternative solution with state of the art light throughput efficiency. (See figure 2)

Figure 3 shows an example of hundreds of spatially resolved spectra acquired simultaneously with the PARISS imaging spectrograph

Go here to compare the spectral properties of prism vs gratings

PARISS imaging spectrograph specifications

  • Weight: 1,250 g (Excluding a camera) Moving parts: None: Optimizes stability and reproducibility. 
  • Dimensions: 210 x 55 x 85 mm
  • Aberration Correction: The wavelength dispersive element is a prism with optical “power.” Concave and convex surfaces on the front and rear surfaces correct astigmatism, coma, and spherical aberration.
  • Spectral range: 365 to ~920 nm or 400 to ~920 nm, depending on choice of camera.  All spectra acquired simultaneously without order sorting filters
  • Light throughput efficiency: Internal transmission ~90% from 450 to ~920 nm.
  • Entrance slit dimensions: Standard 5 mm. by 25 micron, widths of 50 and 100 micron are available in pre-aligned mounting assemblies.
  • Spatial resolution at the sample: Depends on slit width and camera pixel size ~ 0.6 micron by ~0.6 micron with 40x magnification typical.  Nanoparticles may be detected but not resolved
  • Spectral resolution: ~1 nm measured at the full width at half maximum of the 436 nm Hg line, depends on slit width and camera pixel size.
  • Optional calibration standards: Available MIDL wavelength calibration lamp and a “SYLPH”  NIST certified radiometric light source.
Click here for a performance comparison between
a prism and a diffraction grating
An imaging spectrograph images a point on the entrance slit as a point on the detector

Figure 1: An imaging spectrograph images a point on the entrance slit as a point on the spectrum detector as a function of wavelength

PARISS imaging spectrograph configuration showing the prism with curved sides

Figure 2: The PARISS prism with curved sides to enable spatial imaging

An imaging spectrograph can present hundreds of spatially resolved spectra

Figure 3: A very dense set of spectra acquired simultaneously.  Each spatially resolved spectrum correlates with an object projected onto the entrance slit. 

PARISS Videos

Darkfield hyperspectral nanoparticle characterization

Darkfield hyperspectral nanoparticle characterization 

How hyperspectral microscopy works

How PARISS hyperspectral imaging microscopy works

PARISS hyperspectral modes of operation

PARISS hyperspectral imaging microscopy modes of operation

All PARISS Hyperspectral systems are custom configured to meet the needs of an application.
The above configuration is for
guidance only. Specifications can and do change without notice.