Raster scanning is done by taking sequential measurements of the spectra of adjacent regions of a sample by moving the sample point by point or line by line until the region of interest has been covered.
On the other hand, imaging consists of focusing the image of a sample on an array detector and measuring for each pixel the intensity of light at one particular wavelength, much like taking a photograph, but at a single wavelength. In some applications, the power of the laser used in imaging can be orders of magnitude stronger than in mapping, since the power is spread on the whole region instead of a single point or line, thus avoiding the damaging of a sample. Imaging also permits a higher resolution, reduces the acquisition time by orders of magnitude and requires no prior knowledge of the sample contrary to mapping.
Volume Bragg Tunable Filter
What is Volume Bragg Grating? A volume Bragg grating (VBG)
What is Hyperspectral Imaging?
Hyperspectral Imaging Hyperspectral imaging is a technique combining spectroscopy and imaging, where