Spectrometer and method of detecting an electromagnetic (EM) wave spectrum

A spectrometer for detecting an electromagnetic (EM) wave spectrum having one or more wavelength components within a spectral band of interest, comprising:

• an entrance aperture;
• a dispersion and imaging optics containing at least one dispersion element;
• an exit aperture;
• a collection optics;
• and
• at least one single-pixel detector, each single-pixel detector sensitive to one or more of the wavelength components;
• wherein the entrance aperture comprises at least one entrance slit that is spatially encoded along a direction substantially transverse to a direction of dispersion of the dispersion and imaging optics;
• wherein the dispersion and imaging optics is configured to create dispersed images of the entrance aperture on a plane of the exit aperture, such that respective images at the different wavelength components are offset by different amounts of displacements along the direction of dispersion;
• wherein the exit aperture comprises a plurality of exit slits arranged in the direction of dispersion, wherein each exit slit is spatially encoded along the direction substantially transverse to the direction of dispersion;
• wherein the collection optics is configured to gather a total EM wave energy that enters the entrance aperture and exits the exit aperture to one of the at least one single-pixel detectors;
• wherein at least one of an encoding pattern of the at least one entrance slits and an encoding pattern of the plurality of exit slits is adjustable and configured to be changed for a number of times;
• wherein the spectrometer is configured to measure the output signal of the at least one detector for respective ones of the number of times for reconstructing the EM wave spectrum;
• and
• wherein the spectrometer is configured such that an image width of a single one of the entrance slits at a single wavelength is smaller than a spot size of the spectrometer at the exit aperture such that a spectral resolution of the spectrometer is independent of the number of single entrance slits comprised in the entrance aperture.