integral field spectrograph
(integral field spectrometer)
(spectrograph that captures images)
An integral field spectrograph
(or integral field spectrometer)
combines spectrography and imaging, producing
a "cube" of data (three dimensions),
two being spatial (the image) and one being the spectral data
at each specified point.
Its use is called integral field spectroscopy (IFS).
It is commonly a "normal" spectrograph plus an integral field unit (IFU).
A "normal" spectrograph collects data from a narrow line-like area
rather than from a two-dimensional area,
offering spectral data over one spatial dimension.
The integral field unit rearranges
points of light so that the slit includes data across
a two-dimensional area,
paying for this capability by lowering the spatial resolution.
Spectrographs are often built so they can be used with
or without the integral field unit.
- Image slicer directs light from different parts of the image into a slit such that parts of the image across two dimensions are all fed through the one dimension of the slit width. UVES of the ESO VLT does this.
- Lenslet array has a lens for each pixel. SAURON of the William Herschel Telescope (WHT) uses this.
- Fibers uses optical fibers to direct the image into a single slit. INTEGRAL, used on the WHT uses this.
Referenced by pages:
Gran Telescopio Canarias (GTC)
integral field unit (IFU)
VIMOS-VLT Deep Survey (VVDS)